Zenith 24h20 Porthole

[leadlike]

I had the picture tube hooked up, and was rewarded with an out of sync image, but audio and video were of reasonable quality. I removed the crt and flipped the chassis again, changed a few resistors and micas, flipped it again, reinstalled the crt and power up, this time, the 5u4 flamed out. I quickly ID'd a short in the horizontal section, so I dreaded that the flyback was out.

Checking a little more closely, I found that the width coil was missing the inner former tube, making it flop around loosely on its leads. The threaded steel wire that slides in and out of the coil was shorting to it, the adjuster being grounded to the chassis. Essentially, the 5u4 was shorted dead to ground.

With the problem identified, I slipped a cocktail straw into the coil as a new form, and glued the coil back into place. Now the width coil is electrially sound, and still adjustable.