Proscan RCA 36"
Manufactured by Thomson Consumer Electronics Model PS36123
36 Diagonal
older unit 1996

The problem is that the picture shrinks down to a horezental line across the center of the screen.If I tap the TV hard the picture will come back on for a while
I have heard that this generation or model was known for bad solderiing.

Where might the component be located, Which board or component Should I look at to resolder?

Any diagrams or scematics avaible?

Thanks

I HAD A TV LIKE YOUR LAST WEEK THAT SMALL BLACK DIODE BY THE VERTICALOUTPUT IC WAS CAUSEING THE PROBLEM I REPLACED IT AND THAT FIXED THE SET.
I USED A NET 126 2 AMP 1000 VOLT PIV RECTIFER DIODE.

The first thing you can do is find a large transistor on a heat sink and get the number off of it. Do a google search for that number and you will come up with a replacement part. It will tell you what that transistor is, (vertical deflection etc). When you find the vertical output transistor then you have found the vertical circit. Examine the general area for loose soldier joints etc. It sounds like you have a very fixable problem there.

Its the vertical IC dry joint. That is a flat black thing mounted on a plate of aluminium or tin near the transformer with the red wire out of it.