Donkey Kong Jr Cocktail Monitor Problem

[MrD]

I'm having a problem with my monitor in my Donkey Kong Jr Cocktail cabinet.

Until fairly recently, it was working great.  Good color, bright, no burn in.

A month or so ago, when I turned it on, it wouldn't sync, but once it warmed up it was fine.

Then a week or so ago, I left it on overnight and the screen was rolling in the morning and I couldn't adjust it at all.

I ordered the $10 trim pot kit for the Sanyo 20EZ from Bob Roberts and changed those out. They all seem to adjust the screen, but it still won't sync up (or whatever the proper term is).

Attached is a picture of what it shows.  I can get varying images, and in some cases it won't roll at all, but there is still this image scattered image. 

Is my problem these same sync pots, or is it something else?

Do I need to recap the monitor?

If I have to recap it, how do I discarge the monitor since the only way I can see of working on this is removing the monitor up and out, since I can't get to the back?

[qrz]

losing hsync.
could be poor sync connection at monitor.

could be a  faulty b+ filter cap on hVcc, and perhaps a couple of faulty 1uf/50v in h osc/drive

i don't use "cap kits" . so, i do NOT know how complete they may be


qrz

[MrD]

So if that's my problem, any suggestions on how I go about fixing it?

I was hoping I didn't have to pull the monitor, but I'm really resigned to the fact that I'm going to have to.  Which means I should probably recap it anyway  as long as it's out. 

[Kevin Mullins]

Bad solder joints could possibly cause this too.
Wiggle the video input cable a bit and see if it changes anything while watching it.

Check all the connections from the game board to the monitor.
(unplug and replug)

[2600]

Remember DK Jr has the sync pots on the game pcb as well.

[MrD]

Thanks for the replies.  I'll check all my connections again and see if anything seems loose. 

I've tried adjusting the two pots on the DK Jr board itself.  They actually move the image up/down or left/right.  So it moves the entire mess around but doesn't seem to fix the problem, so I don't think that's the problem.

[SirPeale]

If the caps are original, it 100% needs to be recapped.

[MrD]

Well I've resigned myself to the cap kit.  Ordered it up and maybe in a week or so I'll know if this is the problem or not.  It could probably use it anyway even if this isn't the problem.

[Gonzo22]

You screen kinda looks like my donkey kong did as discussed in this topic:http://forum.arcadecontrols.com/index.php?topic=91835.0

I installed a deluxe cap kit from Bob Roberts, and the 20EZ pot relacement kit and my problem cleared right up.

I am convinced that it was the 200k pot (Vert Hold, VR 353) that Paul mentioned in my thread.

It might have been something else, but I followed Peale's advice and replaced the caps at the same time because I already had the monitor tore apart, glad I did too because they were original sanyo caps still on the board which should save me some time in the future. Just my $.02

Hope you get your monitor fixed!

[MrD]

My Deuluxe Cap kit arrived yesterday from Bob Roberts.  He is the man!   

Hopefully I can get it installed soon and see if this clears up my problems.