no picture-sony


  #1  
Old 07-31-00, 06:07 AM
Guest
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i have a sony kv27xbr50 about 10 years old.theset suddenly stop producing a picture.the sound is fine and the channel can be changed with remote,however no other commands are possible.the set was ok when turnedoff in the am,but performed as described when next turned on.no power pops,flashes etc.,to indicate a problem.any suggestions. thanks.
 
  #2  
Old 08-01-00, 09:00 PM
bigmike
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What do ya think Smokey? Flyback? I never really got into TV all though I listened to other techs sitting next to me. I am pretty sure the High voltage flyback can go and leave sound.
 
  #3  
Old 08-02-00, 03:07 PM
Smokey
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Good Afternoon, monk and bigmike:

Bigmke, you are showing your age here, my friend. Television sets haven't used flyback transformers in years. What they do use is voltage doublers, triplers, and quadruplers.

A no picture (black screen) situation does put the problem into the high voltage section of the set, however. This ranges from the horizontal oscillator, through the horizontal driver, HV rectifier, and the voltage quadrupler module. No way to tell for certain which component failed until you get it on the bench and run some diagnostics.

Another circuit, the video amplifier system, will also produce a black screen. In this case, you will have high voltage. You can hear the set "crackle" when turned on. But a zero video will only produce black.

Smokey
 
 

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