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NotTaR of Television Sets : Picture squeezed in then died           
 Copyright © 1994-2007, Samuel M. Goldwasser. All Rights Reserved. Reproduction of this document in whole or in part is permitted if both of the following conditions are satisfied: 1. This notice is included in its entirety at the beginning. 2. There is no charge except to cover the costs of copying. I may be contacted via the Sci.Electronics.Repair FAQ (www.repairfaq.org) Email Links Page.
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Picture squeezed in then died

You were watching 'Knight Rider' reruns and all of a sudden, the picture "squeezed in" slowly from the right hand side. It "squeezed in" about 2 inches or so when the entire picture went dead - has remained like this since. Sound is fine, but no activity at all from the tube. Has it died? How much time, effort, and expense to fix?

No, it's not dead, at least it certainly is not the picture tube.

Your set probably didn't like Knight Rider - at least that episode!

Seriously, how old is the set? Is it a totally solid state chassis or are there tubes in the deflection circuits?

Is there any indication of light on the screen? Any indication of the 15735 Hz horizontal running at all? (You would normally hear the high pitch sound).

Newer TVs almost always derive voltages for the sound circuits from the horizontal deflection but older hybrids may run the sound off of its own power.

In any case, there is a problem in the horizontal deflection and you probably have no high voltage as well assuming no light on the screen.

The fact that it squeezed in first indicates that a partial short or other fault may have developed in the horizontal deflection circuits - possibly the deflection yoke or flyback transformer. It could also have been a bad connection letting loose. Once it failed completely, the horizontal output transistor may have bought the farm or blown a fuse.