Donkey Kong Cocktail Repair Log - Tracking Down Image Shift

[Tighe]

Also with the exception of the H-hold pot and the monitor volume, all the pots on the monitor are new.

Rather than wait for a pot from Bob, why not stop by you local electronics supply store (maybe radio shack if they have it) and replace the pot with a heavy duty one. Check out what I did with my MVS:

The hoizontal postion pot was flakey so I replaced with a heavy duty pot and wired it right into the board. Not the pretty, but it is on the inside, and the cabinet isn't original (4 slot in a 2 slot cabinet)

 

[Mr Do]

Did you check what the 5volts are at the PCB? Not the power supply.

 

[mhanlen1]

Did you check what the 5volts are at the PCB? Not the power supply.

I'll be honest- I don't know how to do this. I would assume there's a pin much like for the B+ and you'd have to place your red lead on the pin while grounding the black lead to the frame? If that's how you do it, I can- but I don't know which board of the 4 to test. Theres labled: clk, vid, sound, and one is not labeled.

Rather than wait for a pot from Bob, why not stop by you local electronics supply store (maybe radio shack if they have it) and replace the pot with a heavy duty one.

Although I thought I read somewhere that radioshack doesn't carry them, I'll do that anyway. I only have two to replace and I don't have to pull the monitor for those. I don't think they're bad, but I guess I should do it anyway. I just check and my volume is a 50k and my H Hold is a 3k. 3k seem awful small a number where all the other pots are much higher. I hope it's right.

 

[Mr Do]

My graphics problems were with the 5 volts being around 4.65
Check the 5 volts at the harness going into the edge connector of the pcb if you don't know how to check directly on the board.

 

[Gonzo22]

Mr. Do I would like to check this voltage like you suggest but my donkey kong doesnt use an edge connector. Would it be like he said to clip red to the test post on the board, and black to chasis? I think I should be able to find what post it is in a manual somewhere.

Anyone know what post it is off hand?

Thanks.

 

[mhanlen1]

Guy posted this on my youtube video of the problem today:

My DK cocktail does this too. Recap'd everything except the video/clock board. I'm thinking its crosstalk in the logic board, since even replacing the monitor doesn't fix the problem.

Figured it be of some interest.

But yeah, the 4 board set doesn't have an edge connector (I think). Doesn't an edge connector look sorta like a Nintendo cart connector?

 

[Gonzo22]

Yeah thats pretty huge for me, that replacing the monitor doesnt fix it.

I was worried it might have been something in the monitor that a doesnt involve caps or pots or repairs that a rookie can do...

I wonder what he meant when he said crosstalk...

Yes an edge connector would look like what you plug an NES cart into, but not the chip in a NES cart.

 

[Tighe]

If you need a monitor, this guy is selling nintendo sanyos, (I posted on another thread)

http://forums.arcade-museum.com/showthread.php?t=98557

 

[gregatron]

If you need a monitor, this guy is selling nintendo sanyos, (I posted on another thread)

http://forums.arcade-museum.com/showthread.php?t=98557

Damn, If only I was closer to NY or knew someone to pick 'em up and ship 'em to me.
Oh well, I might have a good lead on one anyway...

 

[discgolfer72]

hey i just dealt with a simular problem to yours(excpt i had vert crawl) on a mario bros board set
from looking at the manuals it seems the standard dk(cant find the cocktial version manual) and mario bros set are pretty close in comparsion
i would start checking components on your vid pcb on the dk board set since it sounds like you have done almost everything possible to the monitor

look here to see my fix and inital problems if you have not already
http://forums.klov.com/showthread.php?t=98293
http://forums.klov.com/showthread.php?t=98513

im no where close to being an expert on these boards but it seems that you may not be having a monitor ishue it may be a board set problem

from the start i myself was positive that my problem was in the monitor

 

[Tighe]

Damn, If only I was closer to NY or knew someone to pick 'em up and ship 'em to me.
Oh well, I might have a good lead on one anyway...

Did you try asking the guy if he would ship? I would offer to pick them up, but it is a LONG drive for my as I live near Albany NY.

 

[Mr Do]

Oh, right. It is not a edge connector like others, but there are connector plugs.
Either stick the digital probe into the back of the connector, or take the connector out and measure inside the connector to get an idea of the voltage.
There are ways on the board, would someone explain better than me?

 

[Mr Do]

Those Sanyo's for sale are for uprights, not your cocktail.
You gotta check the voltage anyway.

 

[mhanlen1]

Well, this problem is still here. In the mean time I have replaced all 4 SCSI cables, but it didn't fix the issue either. This was suggested by a youtube user who had a cocktail that had a similar issue. He said it solved his problem.

Anyway I logged all the caps on the PCBs and figured I'd shotgun them, just for the hell of it. I need a few things from Mouser, so I figured this would be as good a time as any. I'm ordering them now, so I should be able to tackle this in a week or so.

 

[cleverlyj]

let me know if it fixes it. i've replaced monitor and board pots making mine pretty minor at this point, but it still does it once in a while. i've decided to just deal with it.

 

[mhanlen1]

No dice. Still does it. I didn't replace the pots on the 4th audio board, only because they were replaced at one point a few years ago, and I'm not having audio problems.

Anyway through all of this, I acquired another video issue. It's hard to describe other than a left to right to left to right video roll, where the image doesn't move as much as it looks like all the pixels sort of chase each other. It's like a pixel crawl. It starts out fast moving left and then slows pauses for a second and then all the pixels begin to shift right. It's a little like christmas lights that chase each other. While the total image stays in place all the tiny little dots move.

Anyway, it's completely beyond me now. Game over.