K7203 warms up, then FB squeals and I lose H hold

MC35

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Donor 2011
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Any thoughts on this. After about an hour of being on the flyback begins to squeal and I lose what appears to be horizontal hold.
See attached image. Any thoughts on what I should check?

Thanks,
 

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Caps. And the horizontal hold control.

The squealing is normal when you have the horizontal hold misadjusted on just about any monitor/television. Try it - just adjust the horizontal hold on something, and make the picture all wacky - you'll be able to hear the change. But, your problem is that the monitor is drifting once it's warmed up, usually a problem caused by failing, dried out electrolytics.

-Ian
 
So the problem seemed to go away for a bit. I decied to heat the board up with a heat gun to check some trouble areas so that I can verify if the cap kit will solve this. Cap kit on order.
one thing that kinda worried me was the B+ wasn't real stable. It started out at 124volts instead of 121, then suddenly went up to 180 and shut down. This was prior to me heating the board up. Any reason for that?
 
bad B+ pot failing when up to temp. check for cold solder or cracks on the B+ pot and or in the area of the B+ pot.

Squeal from the fly is when the B+ is crazy high and the sync is off.
 
just looking at the soldering, the cap kit installed by the previous owner isn't the best I've seen. The B+ pot and area look ok, when I re-cap this I will re-flow the joints in the B+ area. I will also pull the pot and verify it is working properly.
Will keep you posted.
Thanks again,
 
O.K. so, new cap kit installed, and a new 5K ohm B+ pot, and B+ doesn't come below 150 volts. Pulling the last few hairs out of my head. Any suggestions on where to check.
 
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