Donkey Kong 3 Graphic issue

stopbutton

New member
Joined
Jun 24, 2017
Messages
20
Reaction score
8
Location
Hope Mills, North Carolina
Good evening everyone,

I have a Dk3 that has been working fine for years. The power supply went out and I replaced it with a happ switcher. The voltages are currently measuring 5.05 at the edge connector on the board. The only voltage I'm not getting from the original is the 24v which was for the coin counter according to the internet.


Above is a video of what it looks like currently. The controls all work and it seems to play fine but its a mess as you can see in the video. Ive taken the chips out and cleaned them and replaced the battery holder and batteries for good measure. Still glithy graphics
 
When the original power supply went out, did it go out while the game was on, or did it just not turn on one day? I was thinking an electrical surge or something that may have taken some chips out.

I'd take a +5v measurement from one of the chips just to see if they are also reading proper voltage.

Thanks,
Jason
 
Donkey Kong 3 at work got big mad with the Happ switcher. I just happened to find an extra Nintendo power block sitting around in the back with a power supply and fixed that up.

the knucklehead that had the game previously was shooting something like 5.6V into the board lol. I had several Fujitsu chips to replace. the -5V apparently has to be near exact -5.00V in order for it to work right, and the Nintendo power supply does that better than the Happ one ever could. I think it has an actual voltage adjustment for it or something. that was last year, I can barely remember what I did last week, so just bear with me here.
 
Also ditch the AA batteries on the PCB. They serve no purpose other than to help corroded traces appear.

Measure the voltage at the caps or chips on the board. DK3 is the most power hungry of the DK boards. Verify your video cable is good between the two board sets.
 
Thank you for the replies. Well ive tried 2 different power supplies now and both are pretty far off. With the 5v set to 5.0 the -5v is at like -4.4. Went up to 5.15 to see if i could get it close but the -5 was still only -4.55. Is there a know power supply that can work?

Also the power supply did go out with the game on so there is a possibility that i could have surged a chip.
 
Like Mecha mentioned also, I had issues with the modern happ power supplies as they didnt provide a good enough -5v power supply to my Dk boards as well.

Best to start with a recap on the oem power supply or get someone to help with that.
 
Get a supply with -12V and add an external adjustable regulator so you can tune the -5V independently of the other voltages.
...or replace the ECL RAM circuit with 5V only RAMs.
 
HudsonArcade, that's an interesting idea to replace the ECL RAM with 5V RAMs! Has anyone ever done this on a DK board?
 
Back
Top Bottom