Current problem is progressively getting worse. While watching tv, pictures shrink a little and you see vertical line breakup at the top and bottom. It only happens for a second and then jumps back to normal. After a few weeks, now sometimes the vertical will shrink entirely to the center of the screen, and the tv will power off. You can power set back on and it runs fine again.
***This set has had its issues in the past. The DM failure, and a problem with the control board on the front of the set. DM repaired, and the front board is no longer used. I just unplugged it and use a remote.
The vertical circuit area is obvious, and there is some electrolytic capacitors, but no obvious failures. I took a couple of the smaller caps out (100uF) and put them on the ohm meter, and they seem to charge up ok. None bulging, or any obvious glue issues that I can see.
Soldered all connections on the vertical chip and surrounding area. Cannot see any obvious connection issues. Also pushed board around with a piece of PVC to see if I could recreate the vertical failure. No luck. Four pin connector for deflection seems sturdy and no need to solder.
Suspect electrolytics or the Vert IC just from a vertical failure standpoint, but I would really appreciate feedback. Problem is intermittent and I cannot seem to recreate on my bench in the garage.
I have the whole chassis removed right now., so component access is easier. I have a decent multimeter, but not advanced equipment like a oscilloscope.
Thanks,
-Todd
Let's hope Larry doesn't see this, because I know he doesn't approve, but if you suspect bad solder, the whack test can sometimes confirm it.
Better yet use a 10x magnifier and good white light while the boards are out. Also while the boards are out look under the crt rack drip line, it's lowest point, for coolant leaks, which would look like just a slight transparent stain on the circuit board.