Donkey Kong (2-board) diagonal lines (fixed)

[ncflagg]

I didn't see a PCB repair forum so lemme know if there's a better place for this.

I'm trying to convert a Nintendo vs Unisystem back to a Donkey Kong. I have a 2 board version. When I turn it on I get the starup sound and some lines, mostly blue, that run diagonal like the horizontal position is way off. I read somewhere that the two vert horiz pots on the video board break often but mine seem to be ok. I can dial them in at 10k ohms. Could the eeproms be bad? How do I know that someone didn't put them in backwards or something?

[SirPeale]

Pop us a picture.

[ncflagg]

The picture rolls/scrolls horizontally (lengthwise because I haven't turned the monitor yet) some of the time and sometimes it stops scrolling and I can see the the image changes to another screen but is still indecipherable.

[SirPeale]

When was this monitor capped last?

[ncflagg]

This is a monitor I have just fixed. It had a bad Horizontal Output Transistor and I did a cap kit at the same time. The monitor runs two Nintendo vs Unsystem boards just fine (Golf and Excitebike). Currently, it has an old HOT from another monitor. I plan to replace it with a new one when they come in.

[ncflagg]

The monitor works fine. Any ideas?

[Kevin Mullins]

I would start off by verifying that you have the SYNC connected correctly for the DK boardset going to that particular monitor.

It MAY be different than the VS. games.
(not sure without looking at all the schematics and manuals myself)

It may also be a bad video output on the DK boardset.

If I remember correctly..... there should be a 50/60 hertz adjustment pot on the 20EZ, might try that.

[ncflagg]

I have tried hooking up to the 36pin connector and also by using a nintendo monitor cable direct to the board with the same results. Would I be able to determine if the video output is bad on the dk board by using a multimeter?

I looked at the manual for the Sanyo 20ezv and haven't seen a 50/60 hz pot. What does it do? Is it also called something else?

[ncflagg]

Well, I pulled out the old DK 2-board pcb today and started testing some resistors and didn't find anything interesting. While shining my flashlight about I noticed on certain ICs there was a black residue almost like rust. The board was pretty dirty so I decided to take out a toothbrush and some water and scrub it down for 45 minutes. I put it back in my cab and  I get picture! My sound quit working but I haven't done any testing on that yet. I'll work on it s'more tomorrow. 

[pcb]

The picture rolls/scrolls horizontally (lengthwise because I haven't turned the monitor yet) some of the time and sometimes it stops scrolling and I can see the the image changes to another screen but is still indecipherable.

Check the two 30/60K pots on the VIDEO board (2nd board in the PCB set).

Best,

 - Mike -

[ncflagg]

I read somewhere that the two vert horiz pots on the video board break often but mine seem to be ok. I can dial them in at 10k ohms.

1st post. Thanks, though. 

[pcb]

So you got it working, eh? 

Best,

 - Mike -