Green Display Problem
The problem you described is more then likely related to the video processor. Possibly also some power supply issue, since the audio section is being effected also. Or this may be two unrelated problems in that case the video processor and the audio processor and amplifier should be suspect. This is how I would handle this problem:
1) Get the schematic for this TV
2) Tackle the video problem first
a) Locate the video processor connect a known video source generator (I use the Sencore VA62A) and take voltage measurements and compare them to the schematic values (For red, green, and blue), if the values are not as they should be, use and oscilloscope to look at the waveforms of the video section and compare them to the schematic values if they are not as they should be, change out the video processor. Retest the TV, this should take care of the video problem.
3) Tackle the audio problem
a) Using the audio section on the VA62A inject a 1000Hz tone into the TV and using an oscilloscope check the input to the audio processor and the output of the audio processor if you do not see a 1KHz sine wave on the output check the voltage levels and compare them to the schematic, if they do nor match change out the processor, if they do match and you see a 1KHz sine wave at the output of the processor, then check the input and output of the audio amplifier stage in the TV if there is no audio at the output change out the amplifier.
This is a good starting point, now I must be frank with you, I run a TV repair business and I do understand that you may not have , Video Signal Analyzer or Oscilloscope, and Video/Audio Signal generator, or even a multimeter to do this job correctly, so since I have told you how I would do this job and you can follow the instructions given and solve your problem, Let me advise you on what you should do,
If I were you and did not have the above equipment nor experience in electronics, I would take the TV to a qualified TV repair center and have it fixed there since they would have the necessary equipment to do the job properly.
I hope this helps,
Jan 21, 2009 |
Televison & Video