Donkey Kong Seeing Double

nerdygrrl

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I was helping a friend today with his Donkey Kong cabaret. *The game wasn't turning on and it had no picture. *I went in and plugged in the monitor made a few adjustments and the best I can get is this. *I like to think of it as twice as good as before....

It was scrolling horizontally before this. *The horizontal hold didn't do much. *Actually none of the monitor adjustments seemed to work. *No contrast or brightness. *Any ideas? *Is this a monitor issue or a board issue?

IMG_2336.jpg
 
I did, the horizontal and vertical pots did nothing. None of the pots, not even the contrast/brightness pots seemed to make a difference on the monitor. I am wondering if the board is shot.

ajcrm125 recommended testing a couple of points on the board.
 
I'd check the video board pretty close see if you see anything broken. Other then that I really wouldn't know what to do. I've been going round and round with these boards recently with nothing to write home about.

http://www.brasington.org/arcade/tech/dk/

This might help you but I don't see your current problem.
 
The games has been sitting in storage for fifteen years. I was surprised I got it to here. The DK board design with the tiny pin connectors just seems flawed. I am beginning to hate early Nintendo design.
 
You could try cleaning the pins on all the socketed chips. If the machine was working perfectly before you put it in might have something there.
 
Update: I have made every adjustment possible on this puppy. To no avail. Have any of you DK guys seen this before?
 
You are seeing double so your vertical scan rate is doubled. The first thing I would try another monitor to confirm chassis or board. Once you have isolated the problem finding the vertical oscillator section and start looking there.

EDIT: Ignore what I posted. The image looked totally different on a mobile phone.
 
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The picture looks normal top to bottom. But left to right it should be quadrants 1 2 3 4. It looks like it is showing 1 4 1 4.

My guess is a board problem, a bad counter or address demux. Need a known working board set or monitor to isolate further.
 
It looks like the high-bit on one of the vertical ( monitor is rotated 90' ) counters is stuck... but since your picture isn't rolling, it's more likely something between the counter and the RAM / sprite logic, like a multiplexer, buffer or register...

I'll see if I can be more helpful once I dig up the schematics...

-Y
 
The picture looks normal top to bottom. But left to right it should be quadrants 1 2 3 4. It looks like it is showing 1 4 1 4.

My guess is a board problem, a bad counter or address demux. Need a known working board set or monitor to isolate further.

Thanks, is it possible to use a normal 2 board DK to test out the cabaret or are the voltages different?
 
Is this what your board is doing, Tighe? You describe seeing a double image, but haven't posted any pictures of the problem, so I didn't have a whole lot to go on.

-Ian

It is the same machine, I posted a youtube video of the problem. Cause not only is the video like this, it also runs double speed.
 
Do you see in Melissa's photo the left and right 1/4 sides of the graphics are doubled on screen and the center 1/2 is not displayed?
 
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