K4900 Monitor Help Please

jeffsgames

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Donor 2011, 2015
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I just capped a monitor for my Time Pilot. It's still acting funny and the pic needs some help. The two main issues I see are that the image isn't evenly spread out (hard to describe). The left is more compressed than the right. This causes the ship to not look centered, and the text on the right actually shows spread compared to the compressed text on the left. The other issue is the picture just looks wavy and full of ripples. The white text at the start of the second wave looks shadows from a dark bleed.

Here's a video. Not the best trying to film using my cell phone and clear a level at the same time. I could have filmed cloverfield! Jump to :22 for the ripple and bleed. The shadowing is not caused by the camera. That's what it really looks like.

Thanks for any advise on what to look for.

 
1) Did you do a COMPLETE cap kit? Go over everything for cold solder (4900 is notorious for cold solder joints)?

2) The compressed/spread video is fixed by adjusting the V-LIN pot. If you have an early version 4900 chassis, you may not have this pot.

3) Hard to see the shakiness with that crappy video. Leave it in attract mode and hold the camera steady where you can see the entire screen...
 
Here's a better video. Hopefully you can see the ghosting of the clouds and the waviness.



I did a full cap kit from Arcadeshop.com. I've heard there are some discrepancies between kits so who knows. I've read that the B+ adjust might cause this, but I'm not sure where that is on this chassis. Any ideas?

This weekend I'll look for the vlin adjust and reflow everything else. Thanks for the tips.
 
The ghosting is usually cap or trace related, so go back over all the caps and make sure you got them all, and inspect the solder to them. There's usually a 1uf50v cap bridging a diode that's not included in the kit, and some models have a 22uf25v cap that isn't included, too.

The 4900 doesn't have a B+ adjustment...
 
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