My fav old stereo PIP set. After a few minutes the vertical narrows down into a 3-4" band across the upper 1/3 of the set. It is erratic, usually goes into this mode after about 5-10 minutes and sometimes comes back out after a half hour or more and long term will stay full screen. I need schematic to diagnose. Any repair tips about this particular old set appreciated.

You dont need schematics, your fault is dry joints on the vertical chip. You probably are going to keep using it till the chip dies so be prepaired to buy a new one. At the moment you can open the set and find the vertical chip, Its a flat chip mounted on a flat piece of aluminium near the high vo;tage transformer. Check http://www.datasheetcatalog.org/datasheet/philips/TDA3654.pdf you will find what it looks like though there are multiple variation. It will be a TDA or an LA, or uPC or if Sharp make it XO. Whilst you are in there with a soldering iron, remove the electrolytics and renew as found.

That's why we pay attention to the forum...what you say makes sense because when the set starts up it is fine, then during warm up period of 5-15 minutes while everything gets up to fully operational temp, there is probably a little displacement at that connection due to the differing expansion rates of materials...then when it is full warmed, the connection happens to become fully restored and functions normally after that for hours. I'm actually going to take it down this next week and do an inspection of exactly what you recommended and a visual of all the usual discolored suspects, also checking the items on the vertical list for proper voltage. Too inconvenient to wait for failure...since I'm not experiencing a total failure, however, I realize the possibility of finding something else is slim since whatever is causing this is temporary each time it is fired up. I'll let you know if I find something different. Appreciate the link with all the data. Brent

If you read my post you will understand that each time you use the TV and it goes to a fail mode the distress tht chip is in is high. What you are doing is taking risks each time you use it. The biggest job you have at the moment is getting the back off, I do not advise you to use it again without soldering the IC. Also forget about looking for burnt things, unless you have a Jewlers loup, the pins on the IC may look OK. ROB

I'm on it. I'll be re-soldering the IC pins. What I was referring to was like my Tosh Rear Proj unit...when I replaced the STK's I also found a couple badly discolored caps, removed & tested them as bad. (I do have an occassional few horizontal lines when tapped on side goes away so prob poor board connection on my re-install) But thanks, I've got the msg and plan to do the IC job tonight.