Toshiba


  #1  
Old 09-06-01, 03:04 AM
bigmike
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I have a buddy with a 5 to 7 year old Toshiba 27" TV. Can get model if needed. Across the top of the screen for aprox. 2" there are several lines. You can also see a shadow of the current program almost as if the vertical adjustment was off but the picture is square in the screen no colapse noticed. No distortion at the bottom. No noise or other distortion. Has been like this he says for many months. Ideas Smokey?
 
  #2  
Old 09-06-01, 03:36 AM
Smokey
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Good Morning, Mike:
That condition is called "vertical overdrive". What you are seeing is the top of the picture has reached it's limits and started back down toward the bottom. The lines you are seeing are vertical retrace lines. In short, the picture is folded back over itself.

Cause? Leaking capacitor between the vertical oscillator and vertical driver stage is usually the cause. The leaking cap allows collector voltages from the oscillator to leak over to the base circuit of the vertical driver. This puts the vertical driver into saturation and the result is a picture that you see on the screen.

Best to get this thing attend to in a short time. If you don't, the end result is smoked vertical driver and sometimes it will also snuff the vertical deflection yoke on the neck of the picture tube.

Smokey
 
 

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