11 year old Zenith goes to static when it warms up


  #1  
Old 05-15-00, 07:14 AM
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My father's 19-inch Zenith, model #SS8915W, started exhibiting this problem
last week. He's in a nursing home, so I'm going to try to save the cost of
a repairman on it. When you turn on the set, the picture is fine, but after
a few minutes, it suddenly gets snowy. At times, you can still see the
picture behind the snow, but only in B&W and very hard to see.

I'm sure this is the fault of some component heating up and then failing,
because if it cools down again, You can turn it back on and it will work for
a few more minutes.

Any suggestions?
 
  #2  
Old 05-15-00, 03:00 PM
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This set has some years on it and I am not going to be inspirational in this answer.

Failure indicates that the problem is in the tuner (channel selector) and is more than likely the RF amplifier transistor that is the problem. As an alternative, it may also be in the AGC (Automatic Gain Control) which may have failed.
The RF Amplifier, of course, amplifies the incoming signal and it's failure is a snowy picture.
The AGC circuit evaluates the incoming signal and will bias the RF amplifier to reduce the signal if the signal is too strong. Conversely, this circuit can fail and overbias the RF amplifier to the point of snow.

If you're adept at electronics, then go ahead. If you are not, stay out of it. The transistor sets are not something you can repair at home anymore. Tubes are gone. You can't just plug-unplug anymore. Now you have IC's (integrated circuits) with 40 little electronic legs on them. You have transistors that look like fly specs on the circuit board. You have special soldering technics.

Take it to a shop? It's going to cost you a bundle because TV shops don't really exist anymore.

Take the advice of an old Electronics Engineer and buy a new set, put the old set in the trash can, and save yourself the grief and frustration.

Sorry I could not be more positive but those are the facts of today's electronics. TV's are "throw-aways". It's cheaper in the long run to just replace them.

Come back and see us often at "Doityourself.com".

Smokey
 
 

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