Dicas Reparação

Modelo - Chassis

Pesquisa: Enviar Dica Resolvida
Resultados 79255
Pedir dica reparação
DARK PICTURE Raster very dark. Chroma information present but no Y signalat output of Y amplifier. I found DC level at Pin 14 of IC401 was veryhigh and no video here as viewed on scope. Disconnecting Pin 14 from PCboard restored the video signal at Pin 14, IC401.
NEON DOES NOT FUNCTION, SEE BELOW No function of neon bulb (NL15) on remote or manual commands.All other functions work. Found only 75VAC at junction of R018 and R017to ground.
WILL NOT STOP CHANNEL SEARCH, REPLACED C159 In the program mode, set would not stop searching when astation was tuned in. M-15 on the M board had the required horizontalpulse. M-9 on the M board had the sync pulse. The positive and negativeAFT voltages on Pins 1 and 2 of M-8 appear to be normal
WEAK PICTURE, REPLACED LEAKY C208 Set had weak video with sync problem.
NO TUNING, REPLACED IC033, CX804 After pressing channel button J none of remaining channelscan be manually selected until remote selection is used, at least once.
PICTURE BLANKING, REPAIRED CRACKED FOIL This unit would rhythmically go from good picture to excessbrightness with retrace lines then to black screen. This would happen atabout a 7 second interval. This would happen continually as long as setwas turned on. The collector voltage on Q704, 705
CHANNEL SEARCH DOESN'T STOP,REPLACED PARTS BELOW All indications were that set would tune properly but wouldovershoot each channel. Result was unstable sync and in general poorpicture quality. Pin 10, IC201 (CX555) AFT was reading approx. 9V vs2.5V. At Pin 2, IC033 (CX804) was reading approx. 10V.
NO REMOTE FUNCTION, REPLACED IC001 Remote does not work, manual OK.
NO CONTROL OF BRIGHTNESS No control of brightness, excessive brightness even withscreens and drives down, voltages OK in ABL drive circuits. Also incolor.
INCORRECT BRIGHTNESS OPERATION WITH RETRACE LINES Excessive brightness and retrace tube cathode voltages low,10V.
NO SOUND OR PICTURE, REPLACED IC2002 No sound or picture. Could not program any channels norwould the set change address positions.
INCORRECT CHANNEL INDICATION The channel indicator neon lamps are polarized and will notlight when soldered in backwards. The lamps are not marked as to whichway they are to be soldered in.
POOR V LINEARITY, R517 INCREASED IN VALUE Poor vertical linearity top 1/3 of picture slightlycompressed. Vertical size control to end of range. Waveform at base ofQ501, blanking pulse 5 msec, it should be 1.2 msec.
DEAD Dead set, 1.6 amp fuse blown, horizontal out transistorshorted, B+ regulator shorted.
INTERMITTENT SHUT DOWN, REPLACED R532 The set would intermittently shut down.

Assistência TécnicaAs dicas apresentadas destinam-se a técnicos de eletrónica, a tentativa de reparação ou assistência sem ter conhecimentos de eletricidade e eletrónica, podem provocar danos mais graves aos equipamentos e, devido a tensões muito elevadas em alguns circuitos, graves danos fisicos que podem constituir um risco em determinadas reparações.

Não arrisque reparar equipamentos com tensões elevadas se não tiver conhecimentos técnicos para o fazer em segurança.

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