| Make | Model | Problem | Solution | Date |
| | | |
| Found: 442
|
| Decca | D Series | Noisy Power Supply in Stand By | Change C806 to 2.2uF 50V | 14-09-04 |
| Decca | D Series | Tuning proc | press 'filled square' button, press '4', search up with '4', down with '4&3'. Press '5' to store chan, press'6' to exit set up | 14-09-04 |
|
|
| Decca | D Series | Improvement of AFC Pull in time and Inter-channel Mute | Change R001 to 18K & R003 to 27K | 14-09-04 |
| Decca | D10R609 | Width lacking | RH04 22R 2w line dr supply res hot - CH09 2200µ 10v | 14-09-04 |
| Decca | D14RFG5 | Lines at bottom when heated | FOP IC TEA8172 | 14-09-04 |
| Decca | D14RFG6 | Dead - no LED | Q404 s/c, Q801 s/c, D805 s/c, R814 o/c & 2A fuse blown | 14-09-04 |
| Decca | D14RFG6 | Goes off aft 10 mins with led flashing 4 times | check R909/R913/R922 all 180K on the crt base | 14-09-04 |
| Decca | D14RFG7 | Shuts down at sw on | s/c in crt htrs to chassis- cut print to earth side of crt htrs & fit 1N4005 between htr pin & chassis | 14-09-04 |
| Decca | D14RKG5 | Sound absent | LA602 choke on spkr/hphone pcb o/c | 14-09-04 |
| Decca | D20RFG5 | Int trips with 4 LED flashes | R909 R913 R922 on CRT Base (All 180K) | 14-09-04 |
| DECCA | D20RFG5 | MY TV POWERS OFF AFTER A FEW SECONDS. IF I SWITCH ON AND OFF SEVERAL TIMES THEN EVENTUALLY THE SET STAYS ON. | replace ALL the electrolytic capacitors in the power supply and this will fix your poor start up.
| 22-08-05 |
| Decca | D20TFG5 | Long time for pic to appear (8 secs after OSD) | G gun on crt was low emission - cleaning cathode restored speedy appearance of pic (for now at least) | 14-09-04 |
| Decca | D21TD6 | No red | R912 | 14-09-04 |
| Decca | D25N 440 | Service adjust proc | PSU Use pot PP1 to adj HT for 151V ± 0.5V for 16:9 tubes at TSP28 terms.
Activating service mode
1. Switch on the appliance whilst holding MENU on set until red LED lights.
2. Release MENU button & press standby on R/C. Defaults to prog l - (make sure test sig is on this chan)
Functsto be selected using P+ & P- keys on R/C.
Control & adjusts = Vol keys.note initial values before adj. In the event of replacing NVM memory or micro, it is nec to make all adjusts accessible in service mode, since replacement memory is supplied without any prior prog & new micro reqs initialization.
1. IF video setting (IFxx AFCxx) adjust reqs special equipment & needed only for ICC2 N1 version,
recognisable by presence of LC7 coil. If the coil is present, adj IF & AFC to values given on label left side of main PCB so that a suitable approx is achieved.
If the coil is not present, adjust as follows:
IF 50, AFC 3
2. Initialization (INIT CTV 831 x (VERSION)
The init proc, which also indicates software version for micro, is enabled with Vol+ key & must be carried out whenever NVM memory or micro replaced.
Initialization has effect of erasing all data from memory except bytes option.
3. Screen grid voltage (Vg2 Test)
Select funct, press Vol+ key. A luminous hor line appears in middle of screen. Adjt pot G2 so that line is just visible (in a dimly lit room). Press Vol- & wait for few secs until service mode is restored.
4. Control bytes (Cox)
These are control registers that must be set as follows:
Co4 00, Co3 27, Co2 96
5. Option bytes (Opx)
Correct values to set for each appliance are given on label on back cover alongside notations Op3,0p2 & Opl.
6. Audio/stereo A2 decoder (LA/SA)
The LA & SA functs allow adjustment of separation between right & left audio chans, & of file respective levels. A RF stereo generator is therefore reqd.
Dis modulation to LH chan & adj LA for 1.4Vp-p at pin 1 of SCART 1 connector.Adj SA for min residual signal at pin 3 of SCART 1. If a stereo generator is not
available/set LA to 01 and SA to OB to obtain a
fair approximation.
7. Setting the luminance/chrominance delay (Yx)
The delay must be adjusted to the following values:
Yp 18 (PAL) (UK VERSIONS)
Ys 30 (SECAM)
Yn 20 (NTSC)
Yo 22 (SCART)
The Yn function is only accessible if signal is NTSC coded (standard accepted only by SCART)
8. On screen display (OSD)
Load fixed value 3F. (AUDIO MENU APPEARS)
9. White control (WB/WG/WR)
Using black & white bar signal, adjust to obtain a correct grey scale.
10. Hor geometry (TC/CP/PW/EW/HSH)
2 groups of these functions, 1 for 4:3 format (suffix 4) & 1 for 16:9 format (suffix 16), both of which must be adjust because they are used in zoom functs (4:3
tubes included). The functs of single parameters -
TC Trapezium correction (4 adjusts appear in 4 X 3 & 16 X 9)
CP Corner parabola correction
PW Parabola correction
EW Horizontal amplitude
HSH Horizontal shift
For 4:3 format tubes, enter EW16 = 3F to ensure proper zooming.
11. Vertical geometry (SC/VSH/VA/VS)
Vertical geometry adj starting with VS (vertical slope), which is set so that central horiz line of test signal is exactly at boundary between the visible image & black part below & must not be changed again. Functions of single parameters -
SC Vertical S-coirection (linearity)
VSH Vertical shift
VA Vertical amplitude
VS Vertical slope
12. AGC tuner setting (AG)
With a signal of ImV applied to ae i/p on UHF chan, adjust to 4Vdc at pin 1 of tuner.
13. De-activating service mode
Once all nec adjusts have been made, press TV or MENU OFF on R/C to memorise and return to normal operating mode | 14-09-04 |
| Decca | D28N440 | Int start up | Dry joints TP6 BD441 & ICP3 TDA8133 on heatsink near chopper | 14-09-04 |
| Decca | D28NE55 | Field collapse TDA8350 cured this but 2 black lines at top of pic | R437 22R o/c | 14-09-04 |
| Decca | D28NEE5 | Excess width & won't come on from st/by | R814 75k, TR801, & ZD813 | 14-09-04 |
| Decca | D28NEE5 | Int dead | R814 75k | 14-09-04 |
| Decca | D28NEF6 | No pic - sound ok | o/c print on scan coils | 14-09-04 |
| Decca | D28NT92S | Dead - went off with crackling | RD17 4k7 1w & RD06 10k 1w overheating & arcing from inside crt - crt faulty | 14-09-04 |
| Decca | D28WT92SN PT92 | Narrow uncorrected pic after s/c LOPTr replaced | Dry joint CD21 which blew BU508AF & CD21 680nF o/c causing RV38 2R2 fusible to go o/c | 14-09-04 |
| Decca | D28WT92SN PT92 | Rush of EHT at start up then set goes off to S/by | Bad joint on CD21, DD07 (BY228) was s/c, and RV38 (2.2 Ohm Fusible) o/c | 14-09-04 |
|
|
| Decca | DBN9B52P B Series | Ballooning pic | Dry joints line scan coill plug on main pcb | 14-09-04 |
| Decca | DBS9892C | Int dead | Dry joints scart conn (12v routed thro it)- remove Nicam pcb | 14-09-04 |
| Decca | DBS9892C | Int dead | Dry joints RA50 & RA16 3w stand up res on audio o/p panel & check joints on 12v reg on main pcb | 14-09-04 |
| Decca | DBS9892C | Int sw off | Dry joints on Audio o/p pcb (12v goes in & out of this panel) & check joints on main pcb (esp regs) & to scart board. Also check/replace R817/819 220R ?w in pri psu & C812 100mfd, C807 100mfd & C806 100mfd | 14-09-04 |
| Decca | DBS9892C | No startup | R817 & R819 in the primary PSU stage (both
220R 0.5 watt) as they looked distressed & all the small caps in PSU (C812 100mfd, C807 100mfd & C806 100mfd) | 14-09-04 |
| Decca | DBS9892C | Thumping noise on audio | dry joints audio pcb | 14-09-04 |
| Decca | DBS9892C | Verticals ragged when cold | C418 470µ 35v o/c between T401 & SCART pcb | 14-09-04 |
| Decca | E series | Dead | R423 in pri of line dr O/C - check Tr403 2SC1815Y | 14-09-04 |