K4600 Vertical Foldover

Shupac

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Just re-capped a K4600. The picture looks good except for vertical foldover at the top edge.

Since I didn't have a kit with new parts, I did the job using electrolytic capacitors I harvested from a not-too-old CRT computer monitor -- so I can't be sure the replacement caps are all OK. Does anyone know whether vertical foldover can be traced to a specific bad capacitor? Which one?

All the resistors in the vertical section of the XY board test OK with the proper resistances. And yes, I reflowed the solder on the connector pins, both on the card and on the main board.
 
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i test all my electrolytics with a capacitance tester before installation
that way i know at least that they are good
love crossing stuff like that off my list when troubleshooting...

try adjusting the "can" on the daughter card with a plastic adjustment tool through the hole in the chassis frame is my only thought
 
Solved. The problem was low B+ voltage, which was caused by a faulty isolation transformer.

The iso I was using was one of those homemade things made by connecting two individual transformers back-to-back. Apparently this iso has high internal resistance, because when it's attached to a load that draws significant current, like the 1 amp or so a monitor draws, its output drops, a lot. I was only getting 95 VAC out of the isolation transformer, which caused the B+ on my K4600 to end up at 100 VDC. When I tried a different isolation transformer, a proper 1:1 iso pulled from a game, I got B+ of 122 VDC (spec calls for 127; close enough). Picture is now bright and sharp with no foldover.

Naturally, now I have other problems -- horizontal width is too big and I have a slight hula. The width problem is probably related to using a swapped tube and yoke; I'll try a different value for the width capacitor. The hula, well... I'll start by unplugging the degaussing coil...
 
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