Fixing a slow roll on a Q*Bert monitor

shilmover

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All,

The monitor in my Q*Bert (I believe its a 4900) has a slow roll on it. I can almost stop it with V-Hold, but it starts to roll very slowly again.

Thoughts on how to fix it?
 
All,

The monitor in my Q*Bert (I believe its a 4900) has a slow roll on it. I can almost stop it with V-Hold, but it starts to roll very slowly again.

Thoughts on how to fix it?

Questions to consider:

1. Has it (the monitor) been capped?
2. Checked the sync pot?
3. Checked the sync pin on the header (reflow?)

That'd be the first 3 things I'd look at.
 
If you run out of things to try, you might want to change the v-hold pot, or pull it out and test it. My Defender had issues with vertical scrolling. I would adjust the pot, and get it to stay (but with great difficulty). It was fine for awhile, and progressively got worse. I just changed all the posts and it is perfect now. That was on a GO7 but you might have the same problem.

I checked all the pots that I pulled out to get a rough reading before putting in the new ones, and the v-hold pot wouldn't lock in on a value on my meter. It kept fluctuating. All the other pots I pulled gave a steady ohm reading. Not sure if that is normal on a failed pot or not.
 
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