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Electronic appliance repair tips database - TV (LCD,TFT,Plasma,Digital), Monitor, VCR, DVD recorder and player, Digital camera, Audio equipment, Microwave ovens, Phone systems, Computer repair
Make
Model
Problem
Solution
Date
Found: 1049
Panasonic
Alpha 3
Colour varies - blue content reduces - int
C352 330pF ceramic cap decoupling Q366 emitter
14-09-04
Panasonic
Alpha 3
Dark blank raster - no sound.
C1251 ( 10nf ) leaky , main microcontroller & memory chips.
14-09-04
Panasonic
Alpha 3
Dark blank raster with no sound or display
No micro activity - dis serial & clock lines to Txt panel to elliminate this cct; set works when this was done - IC3507 was faulty (MAB8461PW13S)
14-09-04
Panasonic
Alpha 3
Dark pic getting worse with time
Q355 2SC3311 on crt base leaky (black level ref)
14-09-04
Panasonic
Alpha 3
Dead - blows R822 4R7 5W & R555 LOP fusible
Line drive wfm dist - C501 0µ1cap in line osc stage leaky
14-09-04
Panasonic
Alpha 3
Dead - LOPTr leaky
Also check R567 1A fuse feeding LOP stage for o/c
14-09-04
Panasonic
Alpha 3
Dead - R555 fusible res o/c in LOP stage feed
LOPTx
14-09-04
Panasonic
Alpha 3
DEAD APART FROM BUZZING NOISE
R555 FUSIBLE RESISTOR OC IF EHT TOO HIGH AFTER REPLACING SUSPECT LOPT
14-09-04
Panasonic
Alpha 3
Dead with LED flickering at sw on
Q823 conducting as opto was turned on; Q825 was sw on because C822 0µ01 ceramic cap leaky
14-09-04
Panasonic
Alpha 3
Dead.
R555 HT feed o/c.
14-09-04
Panasonic
Alpha 3
E-W bowing with no control effect
Check TDA8145 IC701 & R708 & L701 also 0µ01 50v decoupling cap to pin 1 IC701
14-09-04
Panasonic
Alpha 3
Fault Notes: Panasonic Alpha 3 Chassis
See TV Mag July 1994
14-09-04
Panasonic
Alpha 3
Field collapse
C400 10n 50v connected to pin 2 TDA2579A tbase chip
14-09-04
Panasonic
Alpha 3
Goes dark with no sound when heated
C1251 10nF was leaky in micro reset cct
14-09-04
Panasonic
Alpha 3
Goes off aft 3 hours - flashes & shuts down
Check heatsink clip on IC891
14-09-04
Panasonic
Alpha 3
GREEN AND RED "GLITCHES" ACROSS SCREEN , TEXT DISP
C649 ( 120pf ) PIN 3 IC302 PIC TRANSIENT
14-09-04
Panasonic
Alpha 3
INT DIAGONAL BLACK/WHITE STRIPES
D329 ZENER Pt No MA4068
14-09-04
Panasonic
Alpha 3
Int loss of sound & pic
Dry joints prescaler chip inside tuner
14-09-04
Panasonic
Alpha 3
INT LOSS OF TUNING
DRY JOINTS ON PRESCALER IC IN TUNER
14-09-04
Panasonic
Alpha 3
Loss of Video & Audio sigs
Loose panel H due to customer pushing in Scart leads
14-09-04
Panasonic
Alpha 3
No col when using AV connector
Check front AV2 source sw is not set to "S" posn
14-09-04
Panasonic
Alpha 3
No Colour
IC303 TDA3505 vid control chip pin 16 was low instead of 3v - C644 0µ01 ceramic decoupler leaky
14-09-04
Panasonic
Alpha 3
No colour
Ref osc not working; 0µ01 ceramic cap connected to pin 14 IC601 decoder chip leaky
14-09-04
Panasonic
Alpha 3
NO COLOUR PIN 16 TDA 3505 LOW ( NOT 3v )
C644 0.01uF SC
14-09-04
Panasonic
Alpha 3
No g in txt
D3309 o/c - D3308 or D3310 could cause same problem with other cols
14-09-04
Panasonic
Alpha 3
No tuning memory
Chip select signal from pin 53 of micro to memory chip missing - L1209 o/c
14-09-04
Panasonic
Alpha 3
Poor focus - adj focus varies brill
internal leak in CRT between A1 and focus electrodes
14-09-04
Panasonic
Alpha 3
R822 4R7 10W SURGE LIMITER BLOWN , WHEN REPLACED R
REPLACE C501 0.1uF
14-09-04
Panasonic
Alpha 3
Red & Green 'gliches' across screen int
OK in Txt mode - C649 120pF faulty - pin 3 IC302 transient improvement chip
14-09-04
Panasonic
Alpha 3
St/by only
Q825 opto driver hard on. Removing R843 which links base of tr to micro power on/off pin produced a blank raster. Micro reset line stuck at 2v instead of 5v - C1251 10nF was leaky
14-09-04
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