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Repair Flow Chart 107B CM24 GS3 43




A. Power Supply Failure



1. Sympton : check 7106
no startup sound check 7106 pin1 check 7106 check 7106
Ok Ok pin 8=2.4V Ok
LED light off 100V 2V pin4 output ?
3131=24kohm

NO NO NO Ok

check check check
replace 7106 6165/3113/ NO
1101/6102/ 3121/3122/1106
7105/M151 3124/2121/3136 3114/7105


check
check
replace 7106 3128/6107
pin6>8V
/6115



Turn power off
2. Sympton :
check the resistance for
hicup mode with check 7106 check 7106
all output voltages+180, OK
startup sound or pin 6 < 13.5V pin 5 < 0.5V
80,9,13,-13,-6.1,+5,+8 V
blinking LED
check 6148~6159 short?
No No

OPP possibly active
check check 7103 OVP possibly active
No check 3115,3116,
7157/7155/7113/7154 open circuit check 6115
3117,3118,6116,3127
OK
Ok

replace 5101 replace 5101




7106 pin14 OOB
check 7153 pin3 check 7153 pin1
Ok No possibly active
voltage dip 12V< pin1 < 15V
short 7155 pinC

No
Ok
check check check CPU pin 22
+5V loading current 6162/3170/3171 and 7805 emitter
3173/7157/2165



check check 7105 check
3. Sympton:
frequency Ok drain waveform No 6103/3111/6103/
abnormal sound
F=72.5KHZ right? 6108/2128/3112

No Ok

check
replace 5101
3131=24K
44 107B CM24 GS3 Repair Flow Chart


rough check for R, G, B
B.Video 1. video input= 0.7V
Repair Flow 2. 7301video output =2.5V check blanking
3. 7701 video output= 35V swing 7503 pin16

Ok
check
1.Sympton :
R,G,B output
(with wite pattern) check heater check check
Ok No 30<2725<80
no picture =-6.1V EHT=25KV VG1 < -150V
30<2733<80
green LED on
30<2753<80
No
Ok
check Xray prot.
7503 pin2 check DC restoration
check
7722,7732,7752
VG2 > 350V
7721,7731,7751


check blanking
7503 pin16

Ok
2.Sympton :
no video (or dim), check Vg1 check cathod
No turn down Vg2
only raster with/without retrace line Vg1 = 0V +80V/+180V
green LED on
A


check 7301 check 7701 check 7701
check 7301 pin24
Ok pin 6,8,10 pin8,9,11 pin 1,3, 5
2V< ABL < 5V
input swing input swing output swing

No Ok

replace IF
check 7301 replace 7701
cable
pin11 HFLB




check check 7301
No Ok replace 7301
7503 pin16 pin5 CLBL




3. Sympton : check check 7304
check 7301
no OSD or No 7304 pin10 pin2 VCO
pin 2,3,4 input
OSD out of sync. VFLB pin3 RP

Ok

check check check 7304 check 7304
7304 pin12 Ok Ok
7301 pin1 pin5 HFLB pin 7,8(IIC)

No No

replace 7301 replace 7304
Repair Flow Chart 107B CM24 GS3 45



C. Horizontal deflection
output repair flow :


1. Sympton : check Hsync check Hsync check Hsync
without
7604 base 7605 base 7503 pin8
H-deflection.




check check Hsync check Hsync
replace 5613 Ok Ok
180V 7621 drain 7503 pin6

No No

check refer 7503 check list
6412,7627,7628 or replace 7503


check
2. Sympton : check 2614 check 7503
7608/7607/ refer 7503
East /West parabola pin11
7606 check list
corr. exist parabola exist
parabola exist




3. Sympton : enter factory mode check
check 7601
H-linearity check linearity data 3622/3625/
pin 5,6,7
(full freq. range) in eeprom 7609 collector



refer cpu
check
chece list
7610/7612/ replace 5611
check cpu
7614
pin 4,5,6



check check cpu
4. Sympton : check check 7601
3656/3614 7801 pin29
rotation 7602,7603 pin 1,2,3
/3617 control range




check check cpu
5. Sympton : check
7624 collector 7801 pin2
H_dc shift 7622,7623
7625 emitter control range




enter OSD
6. Sympton : check check check
function
Focus 7631collector 7503 pin 32 3607/5618/5613
disable morier
46 107B CM24 GS3 Repair Flow Chart




basic check
D. Vertical Deflection Failure
+13/-13V/+60V




Sympton :
check check
one horizontal line
3414,3428 Ok +60V,6408,6411
V_size is abnormal
good good?
too large/small (small)


No No
Ok


replace replace
3414,3428,7404 6408,6411,7404




check 704
check A
Ok pin2,pin3 ramp
3420,3421
exist ?


No


check
7503
Repair Flow Chart 107B CM24 GS3 47



check cpu pin11/pin32=5V
E. CPU
Basic Check pin9/pin10=12MhZ
check list
pin12/pin31=gnd




check pin1
1. H-linearity
pwm from 0V to 5V




check pin2
2. H-Centering
pwm from 0V to 5V




check pin3
3. Blank normal : low
change timing : Hi
Fh-khz Q5 Q4 Q3 Q2 Q1
<31.00 0 0 0 0 0
31.00 ~33.00 0 0 0 0 0
3,4,5,6,8 (Q5,Q4, check Q1-Q5 33.00~ 36.30 0 1 0 0 0
pin6/pin5/pin4 36.30 ~40.30 0 1 1 0 0
Q3,Q2,Q1) 40.30 ~45.00 1 0 0 0 0
low : 0 45.00 ~50.20 1 0 0 1 1
S-cap switch
hi :1 50.20 ~56.80 1 0 1 1 0
56.80 ~62.00 1 1 0 0 1
62.00 ~66.00 1 1 0 1 1
66.00 ~71.20 1 1 1 0 0
71.20 ~81.00 1 1 1 0 1
81.00 ~88.00 1 1 1 1 0
check pin7 > 81.00 1 1 1 1 1
7. ABL-Adj
pwm from 0V to 5V




1. Normal
check sync. Fvout=Fvin
hin=pin13 2. Self test
13~17 Hsync/
vin=pin16 Fhout=46.875Khz
Vsync
hout=pin14 Fvout=75Hz
vout=pin17 3. sync out of rang
Fhin>72.8 ( or 88.8KHz)
Fvin>168Hz
check pin18
18. Hunlock normal=Hi
blank=low



check pin20
20. 70k / 86k
70khz=low
select
86khz=hi


pin22 pin24
22, 24 P.S. normal hi hi
check pin22/24
LED standby hi low
off low hi
48 107B CM24 GS3 Repair Flow Chart


check
23. Degauss active=hi
no active=low



check check
26, Reset
from 5V to 0V 2814/6808/3827




check
28. Brightness
pwm from 0V to 5V




check
29. Rotation
pwm from 0V to 5V




check
30. VDC shift
pwm from 0V to 5V




check key check 3814,
33. Keypad A
Enter,+,-,bri,con keys 3851~3855



check pin34
1.no H/V sync & IF cable pin5 floating - show msg.
2.H/V sync exist & IF cable pin5 to ground - normal
34. Selftest
3.H/V sync non-exist & IF cable pin5 to gnd - power saving
4.connect a 15k resistor with IFcable pin5 - factory mode
5.connect a 5k1 resistor with IF cable pin5 - burn in mode


check idle status
36,37. DDC bus sda=pin36=hi
scl=pin37=hi

check
check idle status 7804 M24C08
38,39. IIC bus sda=pin38=hi 7503 TDA4856
scl=pin39=hi 7304 LSC4378P2
7301 TDA4886


check pin40 pin41
40,41. EEPROM write : low low
write protection read : don't care
normal : hi hi


pin42
42. USB int hi : active
low : no active
Repair Flow Chart 107S CM23 GSIII 49



Basic check
F TDA4856
. Vcc=pin9=pin10=12V
Vcc > 9V
Check List gnd =pin7=pin25=0v
during startup




1. HFLB pin16
if no exist
(from H.defl) CLBL=hi



pin17 = Hunlock = floating
pin30 = Hpll2 = 0V
pin6 = HDRV = floating
2. Xray
if active pin8 = BDRV = flaoating
(from LOT)
pin12 = V out1 = floating
pin13 = V out2 = floating
pin16 = CLBL= Hi


a pin3 amplify pin5 and it compare to pin4
inhibit pin6 output
b. pin4 generate the saw_tooth wave
3.4.5.6 B+ control if pin3 is pulled to
c. pin5 input voltage for the square output waveform
ground by 7508
d. pin6 pwm output to 7601 & 7602 base




to H_deflection .
8. HDRV
7605 base




to H_deflection
11.EWDRV east/west control
7612 base




differential input
12,13 Vout1/Vout2
to 7401 pin 1, 7




14,15 the input sync from
Vsync,Hsync cpu pin 14,17




Vertical blank will be activated = hi
1.pin30 = softstart pll2 = 0V
2.pin26 = pll1 is unlock in searching mode
16. CLBL
3.pin1 = HFLB no exist
4.pin2 = Xray once actived
5.pin10 = Vcc < 9V
50 107B CM24 GS3 Repair Flow Chart



Hunlock pin is floating while pll1(pin26) is
17. Hunlock
unlock in searching mode




18. IIC sda = hi initial fail could be these of IC
19 IIC scl = hi 7503,7301,7304,7804




20 asymmetr y EW to 7503 pin30
output for soft start




compensate for the V_size
21 EHT_compen.
owing the load variation




22,23,24 pin22 determin the AGC
50Hz< freq. <160Hz
VAGC,VREF,VCAP pin23,pin24 determin frequency A




pin26 determin the
26,27,28,29 pll1 loop filter
30K Hpll1,Hbuf Href Hcap
, , pin 27,28,29 H-Freq
working range




1.compare the HFLBand control the phase of HDRV
30. PLL2
2.softstart




31 EHT_compen. compensate for the H_size owing the load variation




32. Focus to 7631 for the V dynamic focus