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SERVICE MANUAL
CHASSIS CTR-AA
CONTENTS
1.- Technical specifications 2.- Connection facilities 3.- Mechanical instructions 4.- Oscillograms 5.- Print board layout 6.- Electric scheme 7.- Circuit description
7.1.- Small signal processing, Microcontroller/Teletext 7.2.- RGB amplifiers 7.3.- Deflection 7.4.- Sound amplifier 7.5.- Power supply 7.6.- Protections 7.7.- Sets with SECAM L/L systems 7.8.- Stereo sets
Page 3 3 4 5 6 7 - 12 13 13 17 17 17 18 19 19 20 22 22 22 22 23 23 23 25 25 26 27
8.- Electrical adjustments
8.1.- Service mode 8.2.- Power supply and focusing 8.3.- AGC adjustment 8.4.- White D 8.5.- Geometry 8.6.- Options 8.7.- Entering and exiting Plug & Play 8.8.- Error messages
9.- Safety instructions 10.- Service components
2
1. Technical specifications
CHASSIS CTR - AA
Mains voltage Power cons. at 220V~ Aerial input inpedance Min. aerial input VHF Min. aerial input UHF Max. aerial input VHF/UHF Pull-in range colour sync. Pull-in range horizontal sync. Pull-in range vertical sync. Picture tube range : 220 - 240 V ± 10% AC; 50 Hz (±5%) : 35 W (14''), 50W (20''/21''), 55 W (21" Real Flat), 3W (Stand-By) : 75 W - coax : 30µV : 40µV : 180mV : ± 300Hz : ± 600 Hz : ± 5 Hz : 14'' / 21`' / 21" RF / 21" PRF : Mono: 25W 1W (14''), 16W 2W (20''/21'') : Estereo : 2x16W 2x4W (21''), 2x5 W (21" Real Flat) TV Systems : PAL BG : PAL I : PAL / SECAM BG / DK : PAL / SECAM BG / L / L' : On screen display (OSD) green and menu : 1 LED (red in On and blinking red in stand-by
Indications
VCR programs Tuning and operating system UV1315A / IEC (VST)
: 99, 0 (new mask software) / : VST
: VHFa: 48 - 168 MHz : VHFb: 175 - 447 MHz : UHF: 455 - 855 MHz : UHF: 455 - 855 MHz
U1343A / IEC (VST) Local operating functions
: Vol/Prog, +, -, contrast, colour, brightness and sharpness (and hue on program AV with NTSC signal).
2. Connection facilities
Euroconnector 1 Euroconnector 2
Ext 1
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16
-
Audio R Audio R Audio L Audio Blue Audio L Azul CVBS status 1 Green Green Red Red RGB status
Ext 2
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16
-
Audio R Audio R Audio L Audio Audio L CVBS status 2 Chroma Chroma -
(0V5 RMS@ 1K ) (0V5 RMS@ 1K ) ( 0V5 RMS @ 1K ). (0V2 - 2V RMS @ 10K ). (0V7pp @ 75W ). (0-2V int., 10-12V ext.). (0-2V int., 10-12V ext.).
(0V7pp @75W ). (0-V4 int.) (1-3V ext.@ 75W ).
17 18 19 20 21
-
CVBS CVBS CVBS CVBS Earthscreen .
17 18 19 20 21
-
CVBS CVBS CVBS CVBS /Y Earthscreen .
( 1Vpp @ 75W ) ( 1Vpp @ 75W )
Head phone: 8 to 600W. 3,5mm ø.
Mono : 25mW @ 32W Stereo : 2x6mW @ 32W
3
3. Mechanical instructions
For the main carrier two service positions are possible (3.1). A: For faulfinding on the component side of the main carrier. B: For (de) soldering activities on the copper side of the main carrier. Position A can be reached by first removing the mains cord from it's fixation, then loosen the carrier lips (1) and then pulling the carrier panel (2) for approximately 10 cm. Position B can be reached from position A after disconnecting the degaussing cable.Put the carrier on the line transformer side.
Fig. 3.1
A
Fig. 3.2
B
4
4. Oscillograms
5
5. PRINT BOARD LAYOUT
6
+3V3A
7015 *
+3V3 3684 64 2K2 3685 2K2 2628 100N * 7685 24C04 * *
3601 +55 1K5
- TV PROCESSOR - MICROCONTROLER - TXT 3602 1K5 2602 3680 6602 10U
E39 SDA_2
B38 B37 BG/L L/L'
E36 D3 C35 9866 9865 9674 SCL_2 9682
A1
SWB STBY
3682 22K 1
P1.3/T1 2 2608 P1.6/SCL 3 P1.7/SDA
P1.2/NT0 63 P1.1/T0 62 P1.0/INT1 +3V3A 61 9656 2622 100N 60 3629 1K 59 2623 100U 3621 RES 33P 2603 * 33P 2604 * 9613 57 +3V3 9536 +3V3 +3V3 +3V3 2600 RES 9290 GND 54 2612 100N 2601 100U 5601 10U 3295 100R 3294 100R 3293 100R 3292 * 50 1K 6496 * LL4148 2290 * 470P M7:5 3496 1K M7:3 M7:2 M7:1 * M7:4 GND B33 56 5602 2613 100N 10U +3V3 +8A 2032 100U 5033 10U
9763
9608 9609 TP33 24K 7605 * PMBT2369 3607* +3V3A 22K
*
3628 100R 5607 10U +3V3
3603 *
RC5
B34
A1
V_VARI
3612
A2
2609 TP34 3618 1K5
3611 10K 2611 220N
3610 *
15K 2610 220N
3604 * 150 3605 220K
3606 * 10K
* 4 P2.0/TPMW VDDP P3.1/ADC1
*
+3V3A 5 RESET +3V3A 6 P3.1/ADC1 7 P3.2/ADC2 8 P3.3/ADC3 OSCGND XTAL_IN XTAL_OUT
B2 D3 C4
KEYBOARD STBY 9140 MUTE
9618 TP17
3656 22K
+8C
+8C +8
C5
INT/EXT1
9665
1679 12MHz 58
A3
VHFIII 9664
A4
9670 +8 9016 +8
A6
9 VSSC/P 10 P0.5 VPE VDDC
C7 B8 A9 A6 A10
INTEX2 LED 3671 9672
9671
55
9669 VHFI VHFIII UHF 7601* BC847
11 P0.6 12 VSSA 13 SECPLL GO BO VDDA
GND_RGB
TP28 3613 47K 3615 RES 9305 7401 TP16 VGUARD 9371 3410 * 2K7 9496 +55 9417 TP15 3402 390R 2403 47N 2416 100N 3415 3414 RES 9414 +15 9416 3416 2418 RES 2417 100N 9 8 7 6 5 4 3 2 1 TP11 FBACK GUARD OUT_A VFB GND OUT_B Vcc Vi_B Vi_A 9434 3411 2K 1% 3412 2K 1% 2411 2N2 2412 2N2 * * 3406 100R 2308 22N 3407 100R 2309 2U2 9401 * 9061 2001 100U 2003 RES * +5 9402 TP21 JMP 1015 5012 RES 1 5010 1U2 2 3 2005 470N 2367 1N * 19 DECBG 20 AVL/EWD 21 VDRB 22 VDRA 2366 1N * 23 IFIN1 24 IFIN2 25 IREF 26 VSC 27 TUNERAGC 2018 10N 28 AUDEEM/SIFIN1 2102 2092 RES 3008 5K6 * * * PLLIF 36 DECSDEM/SIFIN2 EHT 35 GND2 AUDEXT/QSSO/AMOUT TP10 +8 9102 3104 * +8 3K3 3102 820R * AM_MONO 2111 330P 3101 3K9 2104 1N2 32 NC HOUT 31 SNDPLL/SIFAGC FBISO 33 34 3371 2023 47N 3025 22K * 37 IFVO/SVO VP1 38 CVBSINT +8A 39 47N GND1 40 2034 CVBS/Y NC 42 AUDOUT/AMOUT 43 INSSW2 44 R2/VIN 45 46 2306 1U 3305 10M 3301 15K 2307 4N7 2305 2N2 * +8 5301 10U 2303 100U 2301 220N * 3614 47K 53 TP29 *
B_OUT
B32
A5
D11 EHT
52 TP30
G_OUT
B31
14 VP2 2302 22N 2304 220N * 15 DECDIG * 16 PH2LF 17 PH1LF 18 GND3 G2/YIN B2/UIN BCL/VGUARD CUT_OFF RO
51
R_OUT CUT_OFF VGUARD
B30 B29 A12
A12
M10:1
2299 RES 49
3495 10K
*
*
BCL 48 2298 100N *
D28
2293 * 100N
B_EXT
C27
M10:2
47
2292 * 100N 2291 * 100N 3291 * 100R TP32
G_EXT
C26
- FRAME 3413 6413 *
R_EXT
C25
9435
FB_EXT
C24
*
B13
AM_IF +5A
AUDIO_OUT
C23
CHROMA 2010 CVBS_EXT +8 3030 41 1R 2036 100U 100N +8C
C22
C21
RES
-TUNER -
2002 *
4 3014 * 47R 5 3015 * 47R 3341
3035 100R 3034 * 100R
INT_CVBS
C20
3005
RES
3004 2K A6 VHFIII +8F 3006 2K VHFI
3029 *+5A 3K3 3037* 3K3 2006 22N
3017
2K2
+8F 3002 2K UHF A10 +8F
+8
9010
2007 47N 9011
- IF +5A 6020 3020 2017
39K 1% 2340 100N 180R 3019
3003 100R 6090 5V1 3026* 100R
3031 +8C 180R 2031 100N 7004 * BC857 1K * 3022 * 3023 390R 2021 *
9004 3032 330R TP22 +8C 5032 8U2 1032 3033 * 1K 7005 BC857
SIF
E19
3000
2091 RES 3007* 100R
*
*
3018 27K
A9
29
100N 3027 100K *
1033 3028
- VIDEO EHT D11
A6
A1 V_VARI
A7
3103 1K2
+8
+8
*
9118
2103
2106
30 2101 9103 7104 * BC847
2105 SC_AUDIO_IN
C18
C14
SC_AUDIO_OUT 10U 9091 9092 9093 9094 9095
9497 H_FLYBACK 3372 6372 8V2 3373 * *
D17
A8
GND
GND
9403
9404
9013 9014 B15
LINE_DRV +3V3
D16
TP9
470R
+200
- RGB & DISPLAY COMPONENTS 2202 100N
A-D
7200 6
- DISPLAY 33 L6 3203 7 1K5 B RG 1M1
A32
B_OUT L2:1
3207 560R
3
A31
G_OUT
3214 L2:2 3220
1 9
3216 1K5 GR FF* VG2 FF VG1
23
3221 * R_OUT 9226 A30 3217 L2:3 2 8 3229 1K5 AQUA 3226 1K5
FOCUS
A33
RGB_GND L2:4
TDA6107JF/N3 4
2204 470P
AQUA
5
3236 1K5 2237 2N2 TP20
5235
+200 3205 51R 1M1 L3 3206 2208
L1:3
L2:5
L1:4
6230
L1:1
A29
CUT_OFF
FF
FF
+200
D42
D43
D39
D40
B1 - AM SOUND +8B 3118 6K8 *
2107 * 10N 3117 2K2 +3V3 3626 3K3 L/L' 9122 * * A13 AM_IF 6101 BA682 3114 * +8B 3122 * 22K 3116 10K * 2K2 7103 * BC847
1
K9650M 1101
TP36 4 RES 7125 TDA9830 1 2 3 4 IF_IN NC CAGC CREF NC AM_OUT AM_IN AF_OUT IF_IN NC +8V GND MUTE +12V SW EXT_IN 16 15 14 13 12 11 10 9 2124 4U7 3119 1R 2125 100N * +8B
2 3
5
A37
+8 +3V3 3627 3K3 BG/L
2109 4U7 2108 4U7
5 6 2126 220N E45 AM_AUDIO_OUT B45 * 7 8
9123
D41
D44
FOCUS
VG2
25KV
A38
B2 - AM MONO +8 7106 * BC847 2U2 AM_MONO 3126 1K 3127 47K 2112 B45 A15
3125
AM_AUDIO_OUT
7102 * BC847
26
B3
14"
B4
20"/21"
9686 +3V3 9684 GND GND +3V3
MENU 25 P24 3667 1K3 * 3665 680R *
KEYBOARD
A2
A34
RC5 3635 1K 3636* +3V3 100R 2636 100U 1636 1 2 3 TSOP1836SS3V +3V3 6636 B4_4534 +3V3
9685
3661 1K
1685 1 2 3
P+ 9619
3664 100R 2685 100U
TSOP1836SS3V +3V3 6663 B4_4534
9169
B5 -MONOHEADPH_GND 3191 68R E49 2194 100U 9168 3197* 3199 3198 * * 9166 9167 HPH_R/SPKSW E46 C46 HPH_MONO HPH_L C48
42
1 3 2192 10N 2196
9687
3662
B6
3666 270R 7607 * BC847 3675 1K3 *
11 10 2
*
E47
A8
LED
3670 0R05 3669 1K
*3196
*
3837 3836 470R 3835 * 100R 7878 BC847 3840 1K 2837 100N 120R
+8
- SCART + AV 2825 C52 3892 * * SC1_CVBS_IN 2867 9891 18P LL4148 3872 100R * 6849 *
A-E-F
3877 120R +8 2876 100N
+8 7875 BC847 3874 3814 100R 3875 INT_CVBS 3876 470R A20
SC2_CVBS C55
SC2_CVBS_IN
3838 1K5
3839* 68R 2839 RES *
100R 3870 75R
C54 A21
CVBS_EXT 9296 3865 75R *
C53
AV_CVBS_IN
68R 2866 18P
A22
CHROMA
3846 * * 100R 3871 75R A24
FB_EXT 3855 * 3858 75R * 3845 R_EXT 100R 75R A25
C2
3886 10K *
+8 7876 BC847 *
3885 24k2% 3863 * 2853 8K2 RES 2864 330P *
3883 RES SC2_AUDIO_IN_L E58 3867 10K * A5 INT/EXT1
3898 3896 * 10K
3879
*
75R
LL4148
3880 5K6
3853 *
C1 - SECOND SCART-
6851 * INTEX2 A7
3843 G_EXT 100R A26
3841 B_EXT 75R 3852 * 3854 * 2856 * 2852 3851 * 100R A27
SC1_AUDIO_IN_L E59 3810 *
2851
3861 * E50 SC2_AUDIO_OUT_L 3890 220K SC2_AUDIO_OUT_R 3889 220K * 2863 330P *
* RES 3868 * 8K2 2865 330P 3869
*
SC2_AUDIO_IN_R 10K E57 SC1_AUDIO_IN_R E60 9802 3823 +8 9291 * SWA E56 A18 SC_AUDIO_IN 3856 * 2859 3850
2850
150R 3866 * 150R 2855 330P *
* 3808 *
3860 150R
*
*
9809 220K 220K SC1_AUDIO_OUT_R SC1_AUDIO_OUT_L 3873 330P 3888 * *
2860
E51
*
*
3864 +8 3825 47K C52 SC1_CVBS_IN 3826 22K A20 INT_CVBS
5
C3
2854 * *
GND GND
GND GND
150R
2801 100N
16 3 Vdd
9
7831 BC847
10K 2832 100N
*
3804
100N 2834 18P
14
10K
C55
*
*
4
C8
SC2_CVBS 2833 * * 3830 3803 3802 10K * 3801 8K2 2802 330P 3834 * 75R 100R * 8K2 2804 330P 3805 A21 CVBS_EXT 3714
C53
C54
6865 LL4148 SC2_CVBS_IN 2828* 100N
1 11
10K 3832
+8 3829
2714
3834 *
75R
18P
10
10K
15 12
7822 BC847
3820 22K 3821 10K
A35 SWB
AV_CVBS_IN
6 /E 7 Vee 8 Vss
AV_AUDIO_IN_L
3804
10K
SC1_CVBS_IN
2834*
2
7830 10K BC847 3822 +8
100R
*
8K2 2804 330P
AV_AUDIO_IN_R
C52
3831 RES
C9
VIDEO 3830 *
AUDIO 3803 *
GND GND GND GND GND E63
GND GND GND GND GND E64
C53
E62
E65 A14
- AMPLIFIER + E46 B46 B47 HPH_R/SPKSW 3193
9145 66 + 48 9143 TP35 OUT-_MONO
C6
C72 54
GND
9191
GND
7187C 7187B TDA8943SF OUT2+
3194 RES 7187 TDA8941P OUT+_MONO 8 C71 +13B 3175 RES RES INA+ 3170 MODE IN*
HPH_MONO 9170 +13B 9181 +13B +8
+
+13B +13B +8
+13B 2188 *
1
VCC
GND
-
2154 100N +13B 2190 220N 3154 82R
17 VCC2 16 15 OUT214 13 NC GND2
9
NC
*
8
GND
2
OUT+
OUT-
7
7 IN2+ SVR 6 MODE IN25 IN1NC 4 IN1+ NC 3 OUT1+ VCC1 2 GND1 OUT11
MODE
C66
INA+ +13B
3
IN+
SVR
6 2182 10U INMODE
C66 C70 C69 C69
12 11 10 2193 * 9 2183 1N5 8 7 6 5 2155 +13B 100N 3155 82R 4 3 2 1
SVR
4
C7
+5B
2147 10U 3147 100K *
6147 * LL4148 3140 22K * 7140 * BC847 3142 10K *
3171 10K
MODE
IN-
5
IN-
3145 10K
*
3190
C70 C68 INB+ C73 MAIN_L 3186 3185 RES +13B *
220N 2184* 220N 55 +
IN+
A4
MUTE
3141* 22K
7141 * BC847
3189 +13A 1R 2187 2189 9144 C71 2198 1N5 2195 1N5 2179 220N INB+ INA+ INC66 C72 C69 OUT+_MONO 9151 OUT-_MONO
OUT+
VCC
A23
9113 AUDIO_OUT MAIN_R
3184 * 3183 *
C4
2181* 220N
OUT-
E67
C5
2185 220N
C68 2191 * GND_AUDIO 9196 GND_AUDIO
SC_AUDIO_OUT
AV_CVBS_IN *
13
+8
A,B
- LINE +VCC_LINE 3455 2449 10N 3456 9480 +13C 6446 1N4148 +55 3447 3446 3448 150R 3444 +VCC_LINE RES 2444 47N 2 5441 30882 1 3 3445 47R * 2450 2451 10U 3451 33K 5480 3480 6451 BYT42M TP12 TP13 7445 2445 6447 2446 TP14 2460 47N M10:3 M10:6 8 3462 12K 6463 LL4148 2462 4U7 9464 +8D 3460 EHT BCL A11 A28 2448 3457 2458 5445 10N 5447 47U 2 FOCUS B44 1 25KV 11 VG2 B42 B43
A17
H_FLYBACK
4 2442 560P 3442 5K6 2470 10U
3470 4R7
3452 6470 BYT42M 7 6 3 3235 9 4 3450 1R 1/2W 3238 10 5 5449 10U 3449 1R
6452 +55 BYT42M 2453 22U
A16
LINE_DRV
3440 100R
2440 1U
5440 22U 6440 LL4148 3441 10K *
7440 BF422
+8E +8D
6450 BYT42M 2454 470U TP40 6449 +15 2455 470U 7478 RES
9479 2467 470U +15
+8
M6:1
M6:4
M6:3
TP39 +5 7479 BC337 3477 100R * * +VCC_LINE_A +VCC_LINE TP6 +3V3 100N 2562 2561 22U TP7
+3V3
+3V3
+8
3475 +200 FF FF 470R
B41 +8E 9510 3558 6558 7556 * BC847 * 3557 7550 1 4 3550 100R 7555 2 3556 6 49:1 3501 PTC 1N4007 1N4007 1N4007 2504 6504 6505 2N2 DEGAUSS 49:2 100K 3555 9550
B40
B39
6479 C5V6 2%
D1
50:1
2556 RES 9598 2 2 2500 470N 4 5500 3 9502 9508 9509
2506 3N3 2534 TP1 5525 5534 7 3527 270K 0.5W 2505 8 9575 10 9 3528 270K 0.5W TP5 +13 3571 470R 3570 47R 6570 * 3V3 2% 3576 130R 3525 10R 4 1 5 2 5532 +13 FERRITE 3 3539 3535 1K 3542 1K 3540 RES 3536 39K * 3519 TP18 2533 2531 RES 3531 3534 47K 6531 1N4148 TP19 3532 RES * +VCC_LINE_A +13 3533 22K 7572 * BC847 2532 470P 6541 6540 2540 9542 1540 5538 3573 0R05 7571* BC847 TP8 +13C +13A +13 3541 7575 BC337 RES 6530 BYW36 2530 47U 3572 9504 3530
3504 10M 22
2 1 T 2.5 A H 50:2 1500 9599 RES 1
1
KA5Q0565RT SYNC GND VCC
7514 DRAIN
FB
5
4
3
2
1
2510 1N 6525 BAV21 2514 47U TP3 6511 3526 470R 1N4148 3522 1K2 2524 3N3 6524 1N4148 TP4 9506 6521 RES 2528 RES * 2527 47N 3511 7515 TCET1103G * 6523 BAV21
12
*
5533 FERRITE
1N4007
FERRITE
2502
6502
2N2
6503
6571 RES
POR RES
TP2
2515 47U
- POWER SUPPLY -
*
*
2539 22N 7533 KA431LZ 9507
9572
3537 22K STBY 9667
A3
7701
- STEREO -
1 PCLK 2 NICAM LOR Vddd2
64 2777 470N
5757 FERRITE
+5B
63
A-C
3 ADDR1 3748 A36 SCL_2 9728 3750 100R 9727 3751 100R TP31 6 Vssa1 7 Vdec1 2750 470N 3752 10K 9 P1 2787 RES 10 SIF2 9712 11 Vref1 2751 100N A19 SIF 2740 * 27P 3741 6K8 * 2742 * 120P 5741 22U 2741 180P * 12 SIF1 TP24 13 ADDR2 * 14 Vssd1 9148 +5B 15 Vddd1 2785 RES 2754 1U * 16 CRESET 17 Vssd4 18 XTALI +3V3 3764 C56 20 SWA 2720 RES * 21 SYSCLK 22 GND GND GND GND GND GND_AUDIO 24 SDO2 25 SDO1 26 SDI2 27 SDI1 28 Vdec2 37 TEST1 29 MONOIN 9762 3710 * GND 9710 GND 2782 * C63 AV_AUDIO_IN_R 2783 * C62 E74 AV_AUDIO_IN_L 9714 3763 31 EXTIR 32 EXTIL SCIL1 * 2791 RES SCIR1 33 * 2790 RES 34 3755 15K 3754 15K 2756 * SC1_AUDIO_IN_L 330N 2757 * SC1_AUDIO_IN_R 9761 2K2 470N 30 TEST2 Vssd3 35 MONO_AV E74 SCIR2 2789 330N RES SCIL2 36 2788 330N RES 2781 * * Vref(p) 38 3756 270R 2758 470N * Vref(n) 39 2759 47U i.c. 40 41 23 WS i.c. SCK Vssa2 42 3703 * 330R i.c. 43 RES 3706 100R 6702 C5V6 2% * P2 i.c. 44 45 +8E 2703 RES 3704 1750 24.576MHz 19 XTALO Vref2 SCOR1 46 2760 47U 3702 RES 3705 100R 1/2W 7702 BC337 9704 9703 2702 47U TP41 5702 JMP +5B +5C SCOL1 47 2761 470P * Vssd2 48 2763 470P * Vssa4 49 SCOR2 50 2774 470P SCOL2 51 Vref3 2765 47U 52 2776 470P PCAPR 53 PCAPL 2767 10N GND GND 54 2766 10N HEADPH_GND 9780 9781 B49 55 Vssa3 8 Iref AUXOR 2768 10N 56 AUXOL 2770 10N 57 Vdda 2772 470N 58 3K3 3749 * 3K3 +5B 4 SCL +5B TP27 5 SDA MOR 2773 10N 59 3770 2R2 2771 * 4U7 2769 * 4U7 3769 3K3 3774 33K 7780 BC547 * 3771 3K3 3772 33K * +5C +13B +8E 7781 0R05 3780 * BC547 +13B +8E 3775 330R 1/4W * 2799 HPH_L 100U B47 MOL 2775 10N 60 MAIN_R C67 TP26 61 MAIN_L C73 LOL TP25 62
A39
SDA_2
E1 - MULTI 9722 A33 L/L' 9721
+5B 3742 RES
0R05 3781 * 2798 3773 330R 1/4W * 100U
HPH_R/SPKSW B46
E3 - 2ND SCART2778 2U2 2779 2U2
RES C50
SC2_AUDIO_OUT_L
SC2_AUDIO_OUT_R
C51
3753* 1R 2753 470N
5753 FERRITE
2764 * 2U2 2762 * 2U2
SC1_AUDIO_OUT_L
C65
SC1_AUDIO_OUT_R
C64
E4 - 2ND SCART2780 * 3761 15K 3758 15K SC2_AUDIO_IN_L C58
E2 - MULTI B45 3760 AM_AUDIO_OUT 2755 *
SC2_AUDIO_IN_R
C57
C60
3762
C59
MONO_AV
6. Electric Diagram (Divertisy tables)
21" / 21" PRF *
12
7.- CIRCUIT DESCRIPTION
7.1.- SMALL SIGNAL & MICROCONTROLLER/TEXT (Diagram A)
The small signal is processed by IC 7015. This IC called Ultimate One Chip (UOC) also has an embedded microcontroller. The CTR-AA chassis is designed to use 5 possible IC's in position 7015, 3 for PAL systems, (TDA9350 with teletext; TDA9380 and TDA9370 without teletext) and 2 for multi-standard sets (TDA9351 with teletext; TDA9381 without teletext). The associated circuitry is the same for TXT and non-TXT models. In this chapter 7.1 TV sets with mono sound and PAL systems are explained. The associated circuitry for sets with SECAM L/L' systems is explained in chapt. 7.7, whereas for stereo sets can be seen in chapt. 7.8. The small signal part includes IF detection, video processing, chroma decoder, RGB, sync processor and sound decoder (mono sets). It is fully controlled by the embedded microcontroller. The microcontroller contains a specific program that assures all the functions of the appliance, including 2 menus, one to control the set (see Instructions Manual) and another for Service Mode (see Service Instruct. chapter 8). The IC for TXT sets (TDA935x) contains a teletext decoder, including the following functions: TXT on/off, reveal, freeze, temporary cancellation, clock, subcode, zoom, index, flof, page +/-, X/26 and 8/30 packet decoding (station identification and start-up page).
Fig. 7.1: TDA93XX block diagram 7.1.1.- IF detection IF detection is intercarrier type, that means that sound and picture are detected in the same circuit (PIF). - IF amplifier (pins 23, 24): The IF signal coming from pin 11 of the tuner (1001) is filtered by the IF SAW filter (1015) and applied to IF amplifier of IC7015 by means of pin 23 and 24 input. The IF bandpass characteristic is determined by the SAW (Surface Acoustic Wave) filter. - PLL demodulator (pins 37, 58, 59): The IF-signal is demodulated by means of a PLL detector, which one is used to regenerate the IF reference signal. Reference signal is determined by the PLL loop-filter pin 37 and calibrated by microcontroller crystal (pins 58, 59). It is alignment free. Demodulation is achieved by multiplying reference signal with the incoming IF-signal. - AGC (pin 27): The IF AGC time constant is internally fixed. The tuner AGC voltage (pin 27) is applied to pin 1 of the tuner and adjusted by microcontroller (see chap. 8.3). - Video output (pin 38): This baseband CVBS signal with 2.5Vpp (sync inclusive) of nominal amplitude, contains the FM intercarrier sound signal. Sound is filtered out by a ceramic trap (1032 or 1033) which frequency can be different depending on the system: 5.5 MHz for BG, 6.0 MHz for I system and 6.5 MHz for DK system.
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7.1.2.- Sound processor - FM demodulation (pins 31, 29): FM sound is filtered from CVBS (pin 38) by a loop-filter (pin 31) and demodulated. Decoupling sound demodulator is made by a capacitor on pin 29. - De-emphasis and audio out (pin 28): De-emphasis is made by C2102 at pin 28. The signal at this pin is driven to the euroconnector sound output (see Diagram C) by transistor 7104. - External audio input (pin 35). The External Audio signal from pins 2 and 6 of Euroconnector 1 (or from the Audio in the A/V connector, if the set has one) enters through this pin. The selection of external or internal audio is made through an internal switch, which is controlled by bus I²C (see INT/EXT, chapt. 7.1.8) - Audio out (pin 44): After a volume control (by I²C), this output is driven to the input IN+ of the final sound amplifier IC7187 (Diagram C). 7.1.3.- Video processing - Video switches (pins 40, 42): The internal CVBS signal proceeding of pin 38 is now fed to pin 40 of 7015. External CVBS proceeding from pin 20 of Euroconnector is present on pin 42 of 7015. The IC switches between internal and external are controlled by I²C bus (see INT/EXT, chapter 7.1.8). The selected CVBS signal is internally supplied to the synchronization, teletext acquisition circuits and the video identification circuit for IF ident. - Luminance processor: CVBS is also internally applied to luminance processor, which is composed of chrominance trap filter, luminance delay line and peaking circuits. Sharpness control modifies peaking by I²C. 7.1.4.- Chroma processing This circuit is an internal (no pins associated) automatic decoder for Pal and NTSC systems commanded by I²C bus. - ACC and chroma filter: Video signal coming from video switches is supplied to PAL/NTSC chroma bandpass filter via a variable gain amplifier which is controlled by ACC and ACL detection circuits. The dynamic range of the ACC is 26dB and detects only the burst amplitude. The ACL is a chroma amplitude detector and is active when the chroma/burst ratio exceeds approximately 3. It ensures that CVBS signal to chroma bandpass filter is limited for large. - PLL/DCO: Chroma PLL is integrated and it operates during the burstkey period; the DCO (digital controlled oscillator) generates a subcarrier signal Fsc in phase-lock with the incoming burst signal. The reference signal for the DCO (Fref.) is derived from the crystal oscillator (1679). Different colour frequencies are internally switched by I²C. The hue control rotates the DCO reference phases (H0, H90) from -40 to 40 degrees for NTSC signal via I²C bus. - PAL/NTSC demodulation: The 0ª & 90ª signals are supplied to the burst demodulator circuits to obtain (B-Y) and (R-Y) respectively. Chroma delay lines used in demodulators are internal. 7.1.5.- RGB processor - External RGB inputs (pins 46, 47, 48): RGB inputs coming from euroconnector (see diagram C), are AC coupled (C2291/92/93) and converted internally in YUV signals. Then are switched with internal YUV (YUV SWITCH) by fast blanking. - Fast blanking external (pin 45): When fast blanking is high external RGB is displayed, only if TV is in external AV (program 0). Fast blanking can switch signals for full screen (by a DC voltage) or for a part of the screen (by a pulse voltage). - Matrix: After switching, YUV signals are converted to R-Y, G-Y and B-Y in the internal MATRIX circuit. Saturation control is received by I²C bus. - Black stretcher: Internally the luminance signal is connected to the YUV select circuit and via the input clamps it is supplied to the black stretcher. The black stretcher circuit, fully integrated, extends the grey signal level. This extension is dependent upon the difference between actual black level and the darkest part of the incoming video. RGB adder: RGB signals are obtained in this circuit by adding R-Y, G-Y and B-Y proceeding from matrix and Y proceeding from black stretcher. - RGB OSD: RGB inputs for OSD and TXT are internally inserted to RGB signals. Fast blanking used is also internal. 45). - Beam current limiter (pin 49): The beam current limiter circuit functions as an average beam current limiter (BCL) as well as peak white limiter (PWL). Both functions reduce the contrast and brightness of RGB signals. Contrast reduction begins when Vpin 49 < 3.1V and brightness reduction begins when Vpin 49 < 1.8V. BCL: Average beam current present at pin8 of 5445 (Diagram D) is feedback to pin 49. When beam current is high, voltage of C2462 is lower, D6462 conducts and Vpin 49 decreases. PWL: This circuit is an internal detection circuit, which comes into action if the difference between measurement DC level and white level exceeds approximately 2.6V. Then a current of 200µA is internally produced to discharge 2298 and Vpin 49 decreases. - RGB output circuit (pins 51, 52 and 53): RGB outputs are driven to RGB amplifier (Diagram B). - Continuous Cathode Calibration (CCC) (pin 50): This circuit is an auto-tuning loop which stabilizes the black level (offset) as well as the cathode drive level (gain) of each gun. Pulses in 3 consecutive lines R, G and B (pins 51, 52, 53) at the end of frame blanking are used on alternating fields, one field for black level, following for cathode drive 14
level. Cathode currents of 8mA for black level and 20mA for cathode drive level are stabilized. Cathode current is present at pin5 of IC7200 (Diagram B) and measured on pin 50 (Cut-OFF Info). RGB outputs are adapted to keep cathode currents measured, for example when VG2 voltage is adjusted, DC level of RGB outputs is automatically corrected. - Warm-up detection circuit (pin 50): At the start up a DC voltage of 2.5V is present in the RGB outputs (pins 51, 52, 53). As soon as beam current is detected on pin 50, RGB circuit starts in normal operation. If RGB circuit is damaged or grid 2 is low, the RGB circuit could not start (black picture) due to current is not detected. 7.1.6.- Horizontal synchro - Start up: The horizontal oscillator starts is commanded by microcontroller. During start up circuit provides a softer operating horizontal output with a higher frequency. - Hor. sync. separator: Fully integrated sync. separator with a low pass filter, slicing level at 50% of the synchronized pulse amplitude. - Horizontal Phi 1 detector (pin 17): This circuit locks the internal line frequency reference on the CVBS input signal. It is composed of a phase comparator and an internal VCO of 25MHz (1600*15625). The free running frequency is stabilized using the 12 MHz reference of the X-tal oscillator. Phi 1 detector filter is made by external components at pin 50. Phi 1 time constant is automatically controlled by software for broadcasting signals. For video signals (AV and program 99) constant is always fast to prevent top bending on the screen. - LBF (pin 34): Line Fly Back input, is obtained by the network R3456/C2408 (Diagram D) and R3371/R3372. - Sand Castle (pin 34): Sand Castle output obtained at this pin is used only internally. Levels of sandcastle pulse are 5.3V for burst detection, 3V for line blanking and 2V for frame blanking. - Horizontal Phi 2 detector (pin 16): The flyback position respect line blanking on TRC cathode is controlled by this circuit. Phi 2 detector filter is made by C2305 pin 16. Horiz. shift can be adjusted by I²C (see chapter 8). EHT compensation is made through R3305. - HOUT (pin 33): Horizontal output is an open collector which one drives the horizontal driver stage (T7440 diagram D). 7.1.7.- Vertical synchro and vertical drive - Vert. sync. separator: It is an internal integrator to separate frame sync. pulses from CVBS. - Vertical divider system: The divider system uses a counter that delivers the timing for the vertical ramp generator in the geometry processor. The clock is derived from the horizontal line oscillator. Mode used is automatic 50/60Hz identification with 50Hz priority. - Vertical sawtooth generator (pin 25, 26): A reference current of 100mA is realized at pin 25 by means of an internal reference voltage (3.9V) and resistor R3341. This 100mA reference current is used to derive a 16mA current to charge C2340 (pin 26) during vertical scan. The charge current can be adjusted with the I²C bus control, (VERT. SHIFT). The external capacitor is discharged during vertical retrace by the vertical divider system. - Vertical geometry processor: The saw tooth signal that is derived from the sawtooth generator can be controlled by I²C bus. Control adjustments are: S-CORRECT, VERT.SLOPE, VERT.AMP and VERT.SHIFT (See chapter 8). - Vert. output stage (pins 21, 22): The vertical geometry processor has a differential current output to drive a DC coupled frame deflection (7401). - EHT compensation (pin 36): A voltage inversely proportional of beam current, proceeding of pin 8 of line transformer (5545 diagram D) is applied to pin 36 to stabilize vertical amplitude from EHT variations. - Vertical guard input (pin 50): A vertical retrace pulse proceeding from pin 8 of IC7401, is added to cut-off voltage at pin 50 (this pin has 2 separated functions, cut-off function see chapter 7.1.5). If there is not pulse or its level is not correct (should be above 3.65V, 0.8msec.), the set goes to standby mode. (See chapter 7.6.1 Protections). 7.1.8.- Microcontroller/ Teletext CTR chassis can work with several different microcontroller versions. The numbers that appear at the end of the description of the IC 7015 indicate wich is the software mask version: TDA93xxPS/N2/MMMM. Versions /0586,/0763,/0776,/0946 and /1052 correspond with the same software used in the previous CTU chassis. New software versions, /1196 and /1227, have now been introduced which make it possible to control a chassis with double scart, adding some new features like format function 16:9, which is accessed through the remote control (and with automatic Scart switching), the Plug & Play start up menu and the External and Sleep-timer keys. Following there is an explanation of the different functions of the microcontroller indicating pins number assigned: - Tuning: The different systems available depend on the models in question, these could be Voltage Synthesized Tuning (VST) or Phase-Locked-Loop tuning (PLL). * Voltage Synthesized Tuning (pins 4, 11 and pin 8 or 10): this system works by tuning to a station on the tuner through a linear variation of the tuning voltage (V-VARI) from 0V to 33V applied on pin 2 of the tuner. It is generated on pin 4 of the µC and converted to an adequate level for the tuner using T7605. While searching, µC are always reading internally AFC (Automatic Frequency Control) and video identification 15
signals. When video signal is identified, µC stops searching and do a fine tuning to reach a right AFC value. - Band switching: There are two outputs for band switching pin 11 for VHFI and pin 8 (one scart chassis) or pin 10 (double scart chassis) for VHFIII. The µC controls the channel band in the tuner by a voltage of +5V at the correspondent output. UHF band is controlled by means of transistor 7601. If the set is in VHF, one of the pins VHFI or VHFIII are high and transistor conducts in such a way the UHF voltage is 0V. If the set is in UHF, pins 8 and 11 are low, transistor is cut and the set is in UHF. * PLL Tuning (pins 11 and 8 or 10, depending on the chassis external connectors): The tuning and band switching are totally controlled through bus I²C, which is based between pins 8 (chassis 1 scart) or 10 (chassis double scart) and 11 of the µC, and pins 4 and 5 of the tuner (1001). Neither the varicap voltage nor the band switching is used. Pin 2 of the selector has an extra voltage of 33V, stabilised by the zener 6602 - Control key (pin 5): Pin 5 is activated by a DC voltage. When control keys are not activated, a voltage of 3V3 is produced by R3618. If one control key is activated, this pin is connected to ground directly or by a resistor R3665, R3667 (Diagram B), decreasing its voltage. There are 3 voltage levels depending of the key used: 0V for MENU, 1V for P- and 1.9V for P+. - Mute output (pin 6): This pin is a 3 state output used to control the sound amplifier (see chapter 7.4). States are 0V, open and Vcc (3.3V). In a chassis with new software version it is also used to generate the Standby signal from the source. - INT/EXT1 input (pin 7): The set can switch to external (AV on the screen) by remote control (selecting program 0) or by rise edge at pin 8 of euroconnector (see diagram C). The IC switches internally video and audio to external. In both cases the user can switch to internal changing the channel. If the set includes function 16/9, it will switch to that function directly through INT/EXT (between 4,5 and 7V), although it can also be modified through the remote control. - INT/EXT2 input (pin 8 in a double scart chassis): the TV can switch to the second euroconnector input through the remote control handset (External key), or alternatively through pin 8 of euroconnector 2 (see diagram C). - LED (pin 10 in one scart TV sets or pin 8 in double scart TV set): The LED (D6636 or D6663 diagram B) lights up with a low current when the television set is ON and with a high current when the set is in Standby. While the set is receiving a remote control signal, the led is blinking. - Picture controls (brightness, contrast, colour, sharpness) are processed internally by I²C bus. - Sound controls: Sound controls are processed internally by I²C bus - Standby: When the set is switched to stand by, line stops (pin 33). In addition to this, pin 1 with old software masks, pin switch to low level to make Power Supply in burst mode (see stand by 7.5.4). In new software masks, this function is realized through mute control pin. - OSD outputs: The RGB and fast blanking signals used for On-Screen Display (OSD) and also for TXT are internally inserted to RGB outputs (pins 51, 52, 53). - Oscillator (pins 58, 59): A 12-MHz oscillator is determined by a 12-MHz crystal (1679) between pins 58 and 59. - P.O.R (pin 60): Power on reset (POR) is internal, activated when the set is switched on. If the µC shows abnormal behaviour it is advisable to reset it switching off/on the set. Reset can be done also by a short circuit between pins 60 and 61. - RC5 (pin 62): The commands transmitted by the remote control handset are received by infrared receiver (1685 diagram B) and passed to the microcontroller for decoding. - EEPROM (pins 63 and 64): The microcontroller is connected to non-volatile memory IC7685 (EEPROM) via bus I²C. The following information is stored in the memory: - Channel data including tuning voltage and band of all the channels. - Personal preferences (PP), menu mix and child lock on user menu. - All settings included on Service Menu. 7.1.9.- Supplies and decoupling - Small signal analog supply (pins 14, 39): The same +8V supply coming from line deflection is connected to pins 14 and 39 for small signal processing. A separated supply (C2036) feeds video and sound traps circuit. If +8V supply is not present at pin 39 or pin 14 during the first 4 seconds after switch ON the TV set, the microprocessor goes to Standby mode (See chapter 7.6 Protections). - Digital supply (pins 54, 15): A +3V3 supply is used for digital circuit of TV processor (pin 54). A decoupling capacitor for this supply is present at pin 15 (C2301). Pin 54 is used also to supply the µC. - Bandgap decoupling (pin 19): The bandgap circuit provides a very stable and temperature independent reference voltage of 4.0 V which one is used specially in the analogue video processor part. - µC supplies (pins 54, 56, 61): The µC has several +3V3 supplies, ?Pin 54: Analogue supply (Oscillator, ADC). ??Pin 56: Digital supply to µC core. ??Pin 61: Supply to all output ports of the µC. When the set is in stand by, the µC switch to stand by mode, only 3V3 supplies are present but consumption is reduced.
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7.2.- RGB AMPLIFIERS (diagram B)
The RGB signals available at pins 51, 52 and 53 of IC7015 (Diagram A) must be amplified and inverted in order to reach the level required for driving the tube. The integrated circuit IC7200 (TDA6107) is used for this purpose. RGB inputs (pins 2, 3, 1): These signals are connected to negative inputs of internal operational amplifiers. There is and internal reference voltage of 2.5V for the amplifiers. Negative feedback of amplifiers are internal resistors. RGB outputs (pins 8, 7, 9): These outputs are applied to the RGB cathodes of the tube. Series resistors (3203, 3216 and 3229) are added for flash-over protection. - Cathode current feedback (pin 5): Cathode current used in Continuous Cathode Calibration circuit (See 7.1.5) is obtained at this pin and feedback to pins 50 of IC7015 (Diagram A) - White adjustment: Gain and cut-off point of RGB amplifiers can be adjusted by I²C in the service menu (See chapter 8) - Anti-spot circuit: When the set is switched off, the capacitor 2208 keeps charged and a negative voltage is put at VG1 of the tube.
7.3.- DEFLECTION (Diagrams A, D)
7.3.1.- Frame deflection (Diagrams A) Full bridge vertical deflection output performed by the integrated circuit TDA8357J/TDA8359J (7401). - Frame supplies (pins 3, 6): There are 2 supply voltages, +15V (pin 3) is the main supply and +55V (pin 6) is used to supply the output stage during flyback time. - Vertical inputs (pins 1, 2): (pins 21, 22): The output currents proceeding from pins 21, 22 of IC7015 are converted to voltages by resistors R3411/12 in such a way that 2 inverted sawtooth are present in the differential inputs of amplifier (pins 1, 2). - Vertical outputs (pins 4, 7): Vertical output is DC coupled to deflection coil. That means linearity adjustment is not necessary. - Feedback input (pin 9): A voltage proportional to current deflection is present in R3415/16 and a feedback to pin 9. HF loop stability is achieved by a damping resistor R3402, wich needs current compensation during flyback pulses, wich is obtaniend through R3413 and D6413. - Vertical flyback: This signal is internally added to vertical output (pin 7) using supply voltage at pin 6. - VGUARD circuit (pin 8): This circuit generates a high level during flyback period, and is used to protect the TV set in case of a vertical failure. (See protections, chapter 7.6) 7.3.2.- Line deflection (Diagram D) The final line transistor is driven by the transformer 5441, whose primary winding is driven by the transistor T7440 connected to the line drive output of IC7015 (pin 33). The horizontal deflection stage is carried out in a conventional way, with the deflection transistor (T7445) and line transformer (5445). Beam current info (BCI) is present at C2460. There are the following supply voltages obtained from line transformer (5545): - Frame supply (+15V):Main frame supply present at capacitor C2455. - +55V: This supply is found at the 2455 capacitor and is used for frame flyback, to supply line driver (T7440) and for varicap voltage (+33V, D6602 diagram A) Note: Before the line is started, the driver is supplied by the +13C voltage from the power supply (C2540). - +8V: This voltage is used for small signal circuits and is present at C2467 capacitor. - +5V stabilized: An additional voltage of +5V for tuner (1001 diagram A) is obtained from +8V by D6479 and T7479. - FF: The heather voltage is reduced by R3235/38 and 5235 (Diagram B) to obtain 6.3Veff at the CRT (see CRT table Chap. 10.2).
7.4.- SOUND AMPLIFIER (Diagram C)
Sound amplifier is a Bridge Tied Load (BTL) amplifier including short circuit protection, mute and standby mode. IC used can be TDA8941P for 14" and 17" models, TDA8943SF for 20" and 21" models. Behaviour is the same for both models. - Supply (Vcc, SVR): Main supply (Vcc) is taken from +13A of Power Supply (C2540 diagram D). The IC creates internally a half supply, present in SVR pin and decoupled by 10uF capacitor (C2182). - Sound input (IN+): Amplifiers have differential inputs (IN+,IN-). Audio input is connected to IN+ decoupled by 220nF capacitor (C2181/85) and IN- is decoupled to ground by other 220nF capacitor (C2179). To avoid oscillations there is a 1n5 (C2198/95) capacitor connected between both inputs. - Mode input (MODE): This input is commanded by mute signal proceeding from the µC (pin 6 of 7015 diagram A) and has three modes depending of the voltage level: * Standby mode (Vmode = Vcc): Consumption is very low (used during stand by).
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In this case Vmute=0V, T7657 and T7659 are cut, MODE signal is high * Mute mode (2.5V
7.5.- POWER SUPPLY (Diagram D)
Mains isolated switched mode power supply (SMPS). controlled in variable frequency mode. IC7514 (KA5Q0565RT) includes control circuit and output MOSFET. Output feedback is done by means of an optocoupler (7515). - Switching behaviour: The switching period is divided in on-time, when energy is extracted from the mains into the primary winding (8-12 of 5525), off-time, when energy in the transformer is supplied to the loads via secondary windings of 5525 and dead-time when no energy is extracted or supplied. - Standby mode: Output voltages are present when the set is in stand by. Standby is done cutting line deflection and making the supply in burst mode in such a way that power consumption is very low. 7.5.1.- Degaussing and Rectifier - Degaussing: R3501 is a dual PTC (2 PTC's in one housing). After switch on set, PTC is cold so low-ohmic and so degaussing current is very high. After degaussing, PTC is heated so high-ohmic, so in normal operation degaussing current is very low. - Rectifier: Mains voltage is filtered by L5500, full wave rectified by diodes D6502-D6505 and smoothed by C2505 (300V DC for 220V AC mains). 7.5.2.- Regulation - Power MOSFET (pin 1): Power stage is done by an internal MOSFET between pin1 and ground. Current is sensed by an internal resistor and limited to 5A peak. (See chapter 7.6.2 Protections) - Start up and supply (pin 3): When the set is switched on, a current via R3527 and R3528 is applied to pin 3. When C2514 is charged to 15V, the power supply starts and the internal MOSFET conducts. A voltage across transformer windings is built up. The voltage across winding 4-2 is rectified by diodes D6523/25 and used to supply the IC on pin 3. Voltage of pin3 depends on the output voltage and is about 24V. If Vpin3 is lower than 9V supply stops and if it is higher than 28V, output voltage is limited. (See chapter 7.6.2 Protections) - Sync (pin 5): A pulse voltage proceeding from winding 4-2 is applied to this pin. A delay is added by means of C2524, R3522 and R3526 to synchronize starts conduction of MOSFET at minimum Vds voltage. - Secondary feedback (pin 4): Line supply feedback is obtained at pin 4 by divider R3531/34/19, the differential amplifier (IC7533) and the optocoupler (IC7515). Voltage at this pin is about 1.1V - Output regulation: IC7514 stabilizes output voltage by controlling T-on and so the frequency and the duty cycle. Output control is done by the following way: If line output is higher, current input of the differential amplifier (IC7533) is higher (amplifier has a reference voltage of 2.5V). Current in IC7533 and also in the optocoupler (IC7515) is higher. Voltage in pin 4 is lower, T-on is internally reduced and output is reduced. Output voltage of supply can be adjusted by R3518. 7.5.3.- Secondary side - Line supply: Line supply present at capacitor C2530 should be adjusted to the correct value (depending on the TRC) by means of P3534. - Sound supply (+13V): This supply is used for sound output amplifier and to feed 3V3 stabilizer. - µC supply (+3V3): +5V3 is regulated by T7575, D6570 and T7571. 7.5.4.- Stand by When the set is put in standby, line driver (pin33 of IC7015, diagram A) stops and deflection supply is not loaded. Only a reduced load to supply the µC (+3V3) is necessary. To reduce more the power consumption, during standby T7572 is cut by STBY signal (pin1 or pin 6 of IC7015, depending on software version, diagram A), then current in IC7533 is increased by means of D6531 and output voltages are reduced. As a consequence of this, the supply switches to burst mode operation. During working time C2514 is charged till 12V, then supply stops and C2514 is discharged till 11V.
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7.6.- PROTECTIONS
If TV does not start or it switches to stand by, try to start again in a few minutes and if problem remains check protection pins explained following. 7.6.1.- Protections in IC7015 (Diagram A) - Pins 14, 39: If +8V supply is lower than 6V (pin 39 or pin 14) during the first 4 seconds after switch ON the TV set, the microprocessor goes to Standby mode (See also chapter 7.1.9). - Pin 50: If the vertical retrace pulse at this pin is not correct (should be above 3.65V, 0.8msec) during the first 4 seconds after switch ON the TV set, the vertical guard blanks the RGB outputs and the TV switch to Standby (See also chapter 7.1.7). This protection operates in the following situations: - When the vertical deflection fails and there is no pulse. - When the vertical retrace pulse is higher than 0.9msec. (for example vertical amplitude is too high) - An extra protection is obtained when there is too much current in the CRT (for example +200V supply is missing), because in this case, DC level of pulse is lower by means of cut-off signal. (See fig. 7.6.1)
Fig 7.6.1: Pin 50 correct signal To repair the set more easily, Vguard protection can be disabled, in this case the vertical guard blanks the RGB outputs, but TV does not enter in Standby mode. To disable Vguard, item 8 of Service menu MANUAL C-O should be 01 (See chapter 8.1). Due to a change in MANUAL C-O is difficult to do if the set switch to Standby, Vguard can be disabled also connecting a diode (1N4148) in series with a 2K2 resistor between pins 10 and 7 of IC7015 (Anode at pin 10). Be careful to disconnect this network after the set is repaired. 7.6.2.- Protections in IC7514 (power supply, diagram D) - Over-current: Primary current is sensed on pin 1by an internal resistor for the IC. If this current is increased to 3.5A peak, supply works in an intermittent way (ON and OFF). That can be provoked for a short circuit on secondary outputs. - Lock: If voltage on pin 3 is higher than 28V, over voltage protection limits output voltage. If voltage on pin 3 is lower than 9V the under voltage protection stops the supply. This will not start again until the TV set will remain about 5 minutes switched off in order to allow C2514 discharging.
7.7.- SETS WITH SECAM L/L' SYSTEMS
Multistandard TV is achieved by means of small changes in CTR-AA chassis: - To decoder SECAM signals, small signal IC(7015 diagram A) is changed toTDA9351 for TXT models and toTDA9381 for no Teletext. - To have specific software for multi standard, SYS OPTIONS Item of Service Menu should be adjusted at 04. - For AM sound (standard L/L'), an extra circuit based onTDA9830 (7125 diagram B) is added. 7.7.1.- IF detection (IC 7015, diagram A) - The UOC has an alignment free IF-PLL demodulator. SECAM-L' signals only occur in VHF band I and have their picture and sound carrier interchanged, compared to SECAM-L and PAL-B/G channels. For SECAM-L' the IF 19
picture carrier is situated at 33.4 MHz and the AM-sound carrier at 39.9 MHz. The IF frequency is automatically switched to the right frequency by the microcontroller. (33.40 MHz for SECAM-L' in France and 38.90 for Europe). - The Saw Filter (1015) is changed to a double Nyquist slope filter (K2962).One slope at 38.9 MHz is used for PALB/G and SECAM-L and the other at 33.4 MHz is used for SECAM-L'. - The Tuner AGC time constant should be slower than for negative modulation, because the IC7015 reduces AGC current, so AGC capacitor 2017 is bigger and an extra series resistor 3020 is necessary. To prevent IF over load when jumping to a very strong transmitter (search-tuning), a diode 6020 is placed in parallel. 7.7.2.- Sound processor (IC 7125, diagram B) AM demodulation: In Multi standard sets, also AM demodulation for LL' systems is necessary. AM sound is extracted directly from the tuner instead of from base band video. - AM input (pins 1, 16): IF signal containing AM signal at 32,4 MHz for L system or 39,9 MHz for L', is applied to pin 1 of a double SAW filter (1137). Filter is switched between this two frequencies depending on the system at pin 2 by transistor T7103. -AGC(pin3): C2109 is AGC related storage capacitor. -AM Sound output (pin 6, 7, 8): The demodulated signal is present at pin 6 of IC 7125, goes to pin 7 across C2126, and goes out from pin 8. - AM /FM (mono sets) switching : * For L/L' systems, AM sound goes through 7106 to the pin 28 of Ic 7015. In this case, the FM sound from IC 7015 is muted. * For BG systems, FM demodulation is made using the IC 7015 (seer chapt. 7.1.2). In this IC the AM sound is supressed with a mute signal on pin 12 of the IC 7125, that is obtanied from the mC with the BG/L signal. This signal also cuts the 7102 transistor to avoid the load of the input pin 28 of the IC 7015. 7.7.3.- Chroma processing (IC7015) This circuit is an internal (no pins associated) automatic decoder for Pal and Secam systems commanded by I²C bus.
7.8.- STEREO SETS
The CTR Stereo chassis is based on the TDA9875A chip for NICAM systems (digital stereo) and A2 (analog stereo), and on the TDA9870A chip for only A2 (or Zweiton) systems. This is a single-chip Digital TV Sound Processor for TV sets. In the stereo chassis the sound part in the IC7015 is disabled. All sound signals, analog (Stereo and MONO) and digital (Nicam) are processed in IC7101 (TDA9875A). BG and DK standards use NICAM and A2 sound system, and L and I standard only use NICAM. 7.8.1.- Sound IF (IC 7701 diagram E) - SIF input (pin 12): SIF signal is filtered from video signal coming from pin 38 of IC7015 (Diagram A) by a passband 5.5MHz to 6.5Mhz filter (C2740/41/42 and L5741). - AGC, ADC: SIF is passed through an AGC circuit and then digitized by an 8-bit ADC operating at 24.576 MHz. The gain of the AGC amplifier is controlled from the ADC output. Then signal is separated in 2 ways, one for FM and other for NICAM. - NICAM demodulation: NICAM signal is transmitted in a DQPSK code at a bit rate of 728 Kbit/s. NICAM demodulator performs DQPSK demodulation and feeds the resulting bitstream and clock signal onto the NICAM decoder. A timing loop controls the frequency of the crystal oscillator to lock the sampling rate to NICAM decoder: The device performs all decoding functions in accordance with the "EBU NICAM 728 specification". - FM demodulation: FM signal is fed via a band-limiting filter to a demodulator. If signal is stereo A2, decoder recovers the left and right signal channels from the demodulated sound carriers. A stereo identification signal is sent to the µC. If the signal is FM mono, the IC 7701 demodulates the signal too. - Oscillator (pins 18, 19): The circuitry of the crystal oscillator is fully integrated, only an external 24.576 MHz crystal is needed. 7.8.2.- Controls (IC 7701 diagram E) - Control bus (pins 4, 5): Stereo is fully controlled for the µC of IC7015 (Diagram A) via I²C bus (pins 2 and 3 from IC7015). Status information present in internal registers of IC7101 is read by µC to determine whether any action is required. Control is exercised by the µC also, writing in other internal registers of IC7101. - Audio processing: After demodulation, digital signal is selected (FM, A2 or NICAM) and processed according µC control. Following functions are provided: Forced mono, stereo, channel swap (between channel 1 and 2 with dual signals), spatial effects (pseudo stereo and spatial), Automatic Volume Level (AVL), volume, balance, bass and treble. 7.8.3.- Audio Outputs (IC 7701 diagram E) - DACs (pins 54, 55): Then signals are transformed to analog by DACs and sent to the outputs. Post filter capacitors
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for DACs are at pins 54 and 55. - Sound outputs (pins 60, 61): After a volume control (by I²C), sound outputs (MAIN R and MAIN L) are driven to the inputs IN+ (pins 12 and 6) of the final sound amplifier IC7187C (Diagram C). - Headphone outputs (pins 57, 58): Headphone outputs are driven by followed emitters 7780 and 7781 to the headphones. These outputs are independent of loudspeakers outputs and controls are separated. 7.8.4- Sound Amplifier (IC187C diagram C) The IC used in stereo models could be either TDA8944J (4+4W) or TDA8946J (5+5W). It's a double amplifier, that means 2 supplies, 2 inputs and 2 outputs. - It has very similar characteristics to TDA8941 and TDA8943, being different in that it includes two amplifiers. The modes available are the same as those in IC TDA8941 and TDA8943 (see chapt. 7.4). - Right channel input (IN2+, IN2-): The right side input is connected to IN2+ through a 220 nF (C2181) capacitor, while the IN2- input is decoupled from earth by another 220 nF (C2179) capacitor. To prevent oscillations a 1n5 (C2198) capacitor is introduced between the inputs. - Left channel input (IN1+, IN1-): The left side input is connected to IN1+ through C2184 (220nF), while the IN1- input is decoupled from earth through C2193 (220nF). To prevent oscillation a C2183 (1n5) is used between the inputs. - Sound outputs (OUT1+/-, OUT2+/-): The amplified sound is directed to the attached loudspeakers. 7.8.5.- IC 7701 Supplies - +5V stabilizer: +5V supply for stereo processor is obtained from +12V (C2454 diagram D) by D6702 and 7478. This voltage comes to supply voltages of IC1701 (pins 59, 15, 64) - Digital supplies (pins 15, 64): +5V supplies at pins 15 and 64 are used for digital circuits of stereo processor. Power ON reset (pin 16): When the set starts, C2754 is slow charged by an internal 50K resistor to +5V. When digital supplies are present and oscillator is working, reset is done if pin 16 is low (Vpin16<1.5 V). - Analog supply voltage (pin 53, 59): There is a +5V supply for analog outputs (DACs and operational amplifiers) at pin 59. A 50% reference voltage (2.5V) for these circuits is present at pin 53. - ADC supply voltage (pins 38, 39, 40 and 46): A 3.3V supply voltage is obtained internally and decoupled on pin 38 by C2758. Positive and negative reference voltage for ADC is present at pins 39 and 40. A 50% reference voltage (1.65V) for ADC is present at pin 46. - Front-end supply (pins 7, 8, 11): A separated 3.3V supply voltage (decoupled on pin 7 by C2750) is necessary for IF demodulator. By means of a 200mA current generator at pin 8, a 2V reference voltage is produced at pin 7. 7.8.6.- External connections (Euroconnectors and the AV input) Stereo sets are equipped with 2 euroconnectors and one Audio Video input per RCA connector. Euroconnector 1 has video (CVBS), audio and RGB inputs, while euroconnector 2 has video, audio and SVHS (CHROMA). The euroconnector 1 input is always an internal signal (RF), while euroconnector 2 can be switched between internal and the euroconnector 1 input (copy function). The video switching goes through IC 7801 (TDA4053B), the SVHS and RGB switches in IC 7015 and the audio switches in the stereo IC 7701. The control signals are activated through micro-controller (7015). In the event that 7701 should intervene, it will be controlled by 7015, by means of bus I²C. - Video inputs: The 3 inputs coming from the euroconnectors and the audio jack go to IC 7801. The SWB control signal comes from pin1 of IC7015, while the SWA signal comes from pin 20 of IC7701 and is controlled by bus I²C. The µC controls the switching according to which external input is selected (Ext1, Ext2, AV through SWB signal) and which euroconnector 2 output is selected through the user menu (through SWA signal). - External audio input: External audio (R and L) proceeding of pins 6 and 2 of euroconnector 1 (Diagram C) is applied to pins 33 and 34 of IC7101 and digitalized by an ACD circuit. Audio Inputs from Euroconnector 2 goes to pins 36 and 37. Pins 31 and 32 have the audio input coming from lateral AV connector. Selection between internal or external is done from the µC (IC7015) by I²C bus (see INT/EXT, chapter 7.1.8). - External audio outputs: Signal at pins 47, 48 are driven directly to the euroconnector 1 sound outputs (see Diagram C). Pins 51 and 52 are the euroconnector 2 audio outputs. 7.8.7.- Multi Stereo TV Set (SECAM L/L') - FM and stereo demodulation is done by IC 7701. AM is done by IC7125. - The AM sound output of the IC 7125 is applied to pin 29 of IC 7701, the internal switching being automatic depending on whether we select the demodulation of the AM sound or the demodulation of the NICAM carrier. Then BG/L signal and transistors T7106/7102 are not necessary. - The control signal for L/L systems comes from pin 9 of IC 7701.
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8.- ELECTRICAL ADJUSTMENTS
8.1.- SERVICE MODE
The signal processor IC7015 is fully controlled by I²C, so that the most of adjustments of the set can be made by service menu. - Enter in Service mode: - Select program 75 and press at the same time OSD key (+) on RC and MENU key on local key board during 4 seconds. Service mode is indicated by an S symbol on the down left corner of the screen. Note: Controls (volume, contrast, brightness and saturation) will be pre-adjusted to the mid position. - Display Service Menu: When the set is in service mode it is possible to display Service Menu by OSD key (+) on RC. Using P+, P- keys of remote control the different items can be displayed (see table 8.1):
PARAMETER Nº 1 2 3 4 5 6 7 8 9 10 11 12 13 14
ITEM Description ADJUST VG2 CATH.DRIVE TXT V-SHIFT TXT H-SHIFT V-GUARD DISA AGC START OSD LEVEL MANUAL C-O R CUT-OFF G CUT-OFF BRIGHTNESS CONTRAST R GAIN G GAIN
Value Hex PRG 0C 02 02 PRG 25 02 01 20 20 PP PP 20 20
PARAMETER Nº (*) Nº 15 15 16 16 17 17 18 18 19 19 20 20 -21 -22 -23 -24 21 25 22 26 23 27 24 28
ITEM Description B GAIN S-CORRECT VERT.SLOPE HOR.SHIFT VERT.AMP VERT.SHIFT 16:9 ENABLED 16:9 RATIO SECOND SCART A/V CONNECTOR SYS OPTIONS MENU OPTIONS RESERVED READ STATUS
Value Hex 20 20 20 20 20 20 01 08 00 00 00 00 PRG
Table 8.1. Service menu. Settings are hexadecimal values Note: Column Nº (*) refers to micros with these guards: /0763 /0776 /0946 y /1052 - Pre setting values: When E2PROM is replaced, pre-setting values indicated on table 8.1 are stored by the µC. (see 8.7 E2PROM). - Adjust by Service Mode: When an item is selected, using V+, V- keys of remote control it can be adjusted. Items VGUARD DISA, RESERVED and READ STATUS have fixed values = pre setting values, rest of items see 8.2 to 8.6. - Remove service menu: There are 2 ways to remove service menu - Saving the new settings: Using OSD (+), MENU or INSTALL keys on RC. - Keeping the old settings: Switching the TV to stand by. Service mode continues active. - Remove Service Mode: Switching off the TV
8.2.- POWER SUPPLY AND FOCUSING
- Power supply voltage: Adjust brightness and contrast controls at minimum. Connect a DC voltmeter across C2530 (Diagram D). Adjust R3534 for a required voltage depending on the model and the TRC used (see CRT table, Chap. 10.2) - Focusing Adjust with the potentiometer placed on the line output transformer.
8.3.- AGC ADJUSTMENT
- Connect a pattern generator to the aerial input with RF signal amplitude = 1mV. - Adjust the value of AGC start (item 6 of Service menu) so that voltage at pin 1 of the Tuner (1001) is 3.7V.
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8.4.- WHITE D
8.4.1.- Manual cut-off Item 8 of adjusting values should be 00 (see table 8.1), that means set is in automatic cut-off. However it is possible that RGB do not start (black picture), due to grid 2 is not adjusted. In this case we recommend to change to Manual cut-off (Item 8 = 01), pre-adjust grid 2 to have a good picture and change to automatic cut-off (Item 8 = 0) before continue adjusting (see warm-up detection circuit in 7.1.5) 8.4.2.- Grid 2 - Connect a white pattern generator. - Adjust contrast at 00 and brightness at 36. (00 and 24 in the service menu because hexadecimal values are used) - Put parameter 1 of the service menu ADJUST VG2 = 1. An arrow will be displayed on the left upper corner. - Adjust VG2 potentiometer (in line transformer) till the arrow will be transformed to a square. - In a few seconds, arrow will disappear and ADJUST VG2 parameter will be come back to 00. 8.4.3.- White checking - Connect pattern generator containing grey scale - Adjust the set to normal operation and reduce the saturation control to minimum. - Allow the set to warm up about 10 minutes and check visually if the grey scale has correct colour. - If not, enter to Service menu and adjust G and B gain (items 14 and 15) until a desired grey is obtained. In the case that adjusting is difficult, start again with the setting values of table 8.1 (items 9, 10, 13, 14 and 15).
8.5.- GEOMETRY
- Connect a circle pattern generator with the controls at nominal conditions and enter to service menu. Adjust to have picture centred in vertical position by service menu item 16. - Horizontal shift: Adjust to have picture centred in horizontal position by service menu item 18. - Vertical amplitude: Adjust picture height to cover the screen by service menu item 19. Adjustments only if necessary: - TXT Shift: Vertical and horizontal shift of OSD or TXT can be adjusted by items 3 and 4 of service menu. - Vertical slope: When item 17 is selected, only upper part of the screen can be seen. Vertical slope is adjusted when centre line of the pattern is just visible. - Vertical S correction: S correction can be adjusted by item 20 of service menu.
8.6.- OPTIONS
8.6.1.- System options The chassis system is described in option SYS OPTIONS of the service menu, and the following alternatives are possible: VALUE 00H 01H 02H 03H 04H 05H 06H TDA93x1 - MULTI PAL BG PAL I PAL SECAM BG PAL SECAM BG - DK PAL SECAM BG - L - LP PAL SECAM BG - I - L - LP PAL SECAM BG - I - DK - L - LP TDA93x0 - NOT MULTI PAL BG PAL I PAL BG - I PAL BG - DK
Table 8.2: SYSTEM OPTIONS Adjust
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8.6.2.- Menu Options The various types of menus are described in MENU OPTIONS, and these include the following alternatives:
MENU OPTIONS Menu Bars Basic Bars (NO Scart) Stereo Menu with double Scart Menu only UHF Bars only UHF Basic Bars only UHF (NO Scart) Stereo Menu with double Scart only UHF
VALUE 00H 01H 02H 03H 04H 05H 06H 07H
MONO X X X X X X
STEREO X
X X
X
Table 8.3: MENU OPTIONS Adjust Important note: All the chassis have identification sheet when the chassis type is indicated: "Cod. service: SXXMXX", where SXX means the option of system and MXX means the option of menu Example: S01M00 means: SYS OPTIONS = 01 (Pal I) MENU OPTIONS = 00 (16 Languages menu) When the chassis or the EEPROM (IC7685) have to be replaced, be careful to keep the same type of chassis, setting correctly the chassis options. If the microcontroller detects an incompatible option setting with the chassis configuration, it changes them automatically. This case is only detected first time that the TV set is switch on, and an error message E7 is displayed (see cap. 8.7). Options should be checked according to the identification label.
8.6.3.- Option 16:9 and adjustment of screen format 16:9 (only micros with software mask /1196 and /1227) - Adjust parameter 21 (16:9 ENABLED) in order to activate/deactivate format option 16:9. By adjusting parameter 22 (16:9 RATIO), we modify format ratio 16:9.
16:9 ENABLED Button 16:- not respond. Not scart levels Button 16:9 functioning and Scart levels
VALUE 00H 01H
Table 8.4: 16:9 ENABLED adjust
Picture 16:9 V: 75%
Zoom Conprese
Fig.8.1: Format 16:9 ratio adjust
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8.6.4.- Optional connectors (stereo TV sets) Parameters 23 and 24 of the service menu allow us to configure external connections to the chassis, depending on whether we have double euroconnectors (PAR. 23 = 01) and a lateral AV connection (PAR. 24 = 01).
8.7.- PLUG & PLAY
To exit Plug&Play: 1.- Select your language and press the Menu key (or Install). 2.- Press right arrow key to start tuning 3.- Cancel by pressing Menu key (or Install) 4.- Press Menu key (or Install) to exit the Sort Programs Menu To enter Plug&Play: 1.- Press the Local Menu key and the Install key of your remote control continuously for 4 seconds.
8.8.- ERROR MESSAGES
The microcomputer also detects errors in circuits connected to the I²C (Inter IC) bus. These error messages are communicated via OSD (On Screen Display):
Error message E1 E2 E3 E4 E5 No sound menu E6 E7 E8
Error description New EEprom memory EEprom communication error µC internal error (RA M) Internal bus communication SDA2/ SCL2 bus wrong communication SDA2/ SCL2 bus no communication EEprom data error Not allowed options * (see 8.6) Vertical guard protection
Component Adjust needed IC 7685 IC 7015 IC 7015 IC 7701 (stereo) IC 7701 (stereo) IC 7685 Item 21 y 22 service menu Pin 50, IC 7015
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10. Replacement parts list
10.1 Electrical
CTR-AA CHASSIS
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10.2 Electromechanical
CTR-AA CHASSIS
POS.
2 2 3 4 4 4 5 5 5 5 6 7
DESCRIPTION
DEGAUSSING COIL 14" DEGAUSSING COIL 21" LOUDSPEAKER 3" 1.5W 25 OHMS TV 14" MONO LOUDSPEAKER 50x90 3W 16 OHMS TV20/21 MONO LOUDSPEAKER 50x90 3W 8 OHMS TV20/21 MONO LOUDSPEAKER 58x126 6W 16 OHMS STEREO REMOTE CONTROL MENU TXT REMOTE CONTROL MENU NO TXT REMOTE CONTROL RF25 STEREO REMOTE CONTROL BARS NO TXT LOOP AERIAL ROOD AERIAL ANLY FOR EIRE
CODE
313E 108 21641 313E 108 67781 3130 100 60191 3130 100 20401 3130 100 60301 3130 100 60931 3130 108 21431 3130 108 21441 313W 108 21711 3130 108 21481 3130 100 20482 3130 100 20361
SAFETY
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10.3 Mechanical, chassis and switches
CTR-AA CHASSIS
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313010526341