I have not dealt with this issue directly on .  These issues are sometimes difficult to pinpoint.

Mike's Arcade repair log mentions the following:

03/21/2002

Problem: Sparklies or Graphic glitches.

This is a pretty common problem on DKjr and DK boards, but this is the first time I've found a cure.
This particular board was fine until I let it run about 1/2 hour. I had upgraded it to DDK and when testing it as a Jr board saw no problems, but didn't' let it run too long before I upgraded it.

After the upgrade, I let it sit and burn-in while I went to eat dinner. When I came back, the top or the screen above Polly screaming help in DK was filled with glitches! I booted over to DKJr and the key on the top exhibited the same problem with sparkly glitches. So, I grabbed a can of freeze spray. All the ECLs were really hot to the touch, so I hit them one at a time, then watched the screen. The faulty chips was a MC10124 at 4H, this chip is a quad TTL->MECL translator. The MC10125 is it's counter-part and goes from MECL->TTL.

After letting it run another 1/2 hour or so, in DK mode I noticed just a few sparklies at the top, under the high score. So I shot the MC10125 at 4F with freeze spray and watched for more sparklies. As long as I shot the chip every couple of seconds, the sparklies didn't show up. If I waited a few minutes, they would again appear. Changing both chips solved the sparkly problem with this board.

Solution: 2 bad ECL translators, an MC10124 at 4H and the MC10125 at 4F.

https://www.mikesarcade.com/arcade/repairs/dkjr.html

Thanks for helping out on my DK repair!

Welcome to the forums.

Awesome photos!