What is up with my Donkey Kong monitor

ArcUnderground

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I have a problem with the Sanyo 20ez in my Donkey Kong. It works most the time, but intermittently starts acting like it has a horizontal sync problem (drooping on the left side some times, appearing scrambled, jitters). Here's a video of the problem:

http://www.youtube.com/watch?v=GCAbJguWc5c&feature=plcp

The flowchart seems to indicate it is time for a cap kit, but I've read several posts about cap kits not fixing jitters. I've tried cleaning all the pots with component cleaner to no avail.

Any idea what is wrong with it?

Trent.
 
Clean the pots on the actual DK board too, there should be 2 of them on the one end of the board. They control vertical and horizontal adjustments.
 
had the same issue

I would say that it looks like a problem I had on mine. I did an entire cap kit and it went away but it is more than likely an issue with cap c459 according to Randy Fromm. He has a bunch of monitor trouble shoot info posted all over the internet.
 
So this will likely be my first cap kit. The monitor is otherwise perfect so I was hoping for a simpler solution (aren't we all).

One other tidbit - the issue can be resolved (or started) by giving the thing a good knock.
 
I feel your pain. Pulling the the monitor out is kind of a pain. But there is a step by step instruction set for it. If you PM me your e-mail address I will send you a pdf of the instructions.
 
The easiest way to work on a 20ez is to remove whole monitor. Then remove chassis from frame. Get a cap kit with the audio board cap kit also.

Andrew
 
I have a problem with the Sanyo 20ez in my Donkey Kong. It works most the time, but intermittently starts acting like it has a horizontal sync problem (drooping on the left side some times, appearing scrambled, jitters). Here's a video of the problem:

http://www.youtube.com/watch?v=GCAbJguWc5c&feature=plcp

The flowchart seems to indicate it is time for a cap kit, but I've read several posts about cap kits not fixing jitters. I've tried cleaning all the pots with component cleaner to no avail.

Any idea what is wrong with it?

Trent.

Before you get all crazy with doing a whole cap kit on the monitor, make sure you've tested your b+ voltage and adjusted your horizontal hold pot.

Search the forums for how to's on setting your b+ to 108 volts, and adjusting your horizontal hold pot to lock in your image.

I'd bet your b+ is low.
 
B+ is 109.4

I can fix the problem temporarily with the h hold pot, but it is unstable (the problem comes back). Adjusting the h hold again will fix it, but again only temporarily. I've sat there turning it back and forth about 1/4 turn as the problem appears and can dial it in every time but the problem will resurface.
 
I had a problem with my sanyo 20ez that sounds just like yours. I popped on a new cap kit for the first time and it worked perfect after that.
 
sanyo

also be very careful when removing the chassis. these are old and brittle. more damage is done removing and installing these than anything else. DO NOT HOLD IT WITH ONE HAND.IF YOU THINK YOUR BEING CAREFUL ENOUGH, THEN BE A LITTLE BIT MORE.
 
So this will likely be my first cap kit. The monitor is otherwise perfect so I was hoping for a simpler solution (aren't we all).

One other tidbit - the issue can be resolved (or started) by giving the thing a good knock.

Sounds more like a bad solderjoint somewhere if its responding to some knocking..

Anyway, a capkit never hurts as all of the caps are probably 25 years old.
 
I took the easy way out and threw in a rebuilt chassis. Having removed the old one I can see it has been recapped somewhat recently. Solder job looks pretty rough so etienneodk you are probably right. At some point when I have more time I'll reflow some of the points on the back and give it a try.
 
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