Fixing Zenith CCII Avante 25JC49

[Electronic M]

If the convergence diodes are all in a milti-pin module they're probably selenium and could be bad. Also if the convergence yoke isn't lined up right on the neck that can cause issues.

[drwatson32]

Thanks! It looks like I've got 13 discrete diodes all over the convergence board. I'll have to lift an end of each to check them out, on the to-do list while I have the board removed.

[vol.2]

My first thought was also the yoke. I've had convergence issues that turned out to be purity issues and vice versa.

Assuming all your diodes are checking okay and nothing it obviously wrong, you probably want to start from square one and reseat the yoke etc with best purity and everything in the middle

[drwatson32]

That could be, the purity adjustment wasn't fun and maybe not 100% perfect, I'd call it 99%. Not only did the yoke not move enough to get to where I could see where the red spot (in it's entirety) was, but the lateral magnet/purity ring assembly is either a weird design that puts the rings behind the magnet, or it was installed backwards. I do wonder if it can be turned around so that the rings are easily accessed. Of course, that would put the clamp up near the convergence magnets. I used a permanent marker to indicate exactly where this was positioned, but I could imagine having to circle back to fixing purity when reassembled, anyway.

This is the side that has been facing out:


The rings are tucked behind. I haven't seen another CCII photo with this particular assembly. The grainy pic in the SAMS seems like it *might* be the same, though.

[drwatson32]

Good evening! I ended up checking all of the diodes and replaced all of the carbon comp resistors. Upon reassembly, I found that some of the adjustments for red and green magnets were no longer working. I removed all 3 magnets and found that the red and the green each had an open coil. The connections looked to be corroded. I was able to fix both sorry looking ends of the bad red coil. Sadly the green magnet is now FUBAR. (I actually managed to solder if but broke it when snipping off excess wire. bummer)

Does anyone happen to have any of these from a neck board kicking around? Numbers on the magnet are S-94731 273S7722

[vol.2]

Originally Posted by drwatson32

Sadly the green magnet is now FUBAR. (I actually managed to solder if but broke it when snipping off excess wire. bummer)

I have seen people just replace the ends of the wire with new wire. As long as you don't alter the number of turns a great deal, they should still work within adjustment range.

I do know what FUBAR means, but perhaps you can peel the onion back a little more than you thought you could, and try to solder a new wire onto the ends.

[drwatson32]

Originally Posted by vol.2

I have seen people just replace the ends of the wire with new wire. As long as you don't alter the number of turns a great deal, they should still work within adjustment range.

I do know what FUBAR means, but perhaps you can peel the onion back a little more than you thought you could, and try to solder a new wire onto the ends.

Aye, that's where we ended up once I carefully unraveled it a bit, trying in vain to find the new end. It became a mess, unfortunately.

I am looking forward to trying adjustments again once I find a donor- I've only had particularly good luck with moving blue around, and now that makes a bit more sense.