Donkey Kong Forum
General Donkey Kong Discussion => General Donkey Kong Discussion => Topic started by: xelnia on May 19, 2018, 03:51:46 am
-
Mates,
My DK board has been acting up for quite awhile and I'm at my wits end on how to fix it. Basically, every moving sprite is wigging out. It seems to get a little worse the longer the board is powered on, but settles into a certain pattern of glitchiness. I've recorded a video to show what's going on, and ran through every type of board as well as attract mode. No audio because I forgot to turn on the mic. Here's everything I've tried so far:
-New switching power supply. The old PSU was dead anyway, so I got the Arcadeshop PSU adapted for Nintendo cabs. Turning up the voltage actually helps, but it goes beyond what I'm comfortable sending to the board. I fried a Remix kit trying to do it this way. The glitches are present with no kit in, and also present when the two different Remix kits I have are installed.
-Replacement original PSU. I've seen posts around the intarwebz stating that switching power supplies don't always play nice with older PCBs. So, I got a whole new power brick from TNT...power supply, isolation transformer, etc. All voltage from the PSU and at the board is fine. -5.28, +5.28, +12.43, and +23.7 from the PSU. -5.35, +5.03, +12.32, and +23.6 at the edge connector. +5.03 at every single chip I tested (probably 20-30 chips on both the CPU and video board).
-Cleaned the board and removed, cleaned, and reseated all socketed chips.
-Checked all cable connections.
-Mike's Arcade originally fixed this board for me, when it was completely dead. He replaced the NE556 timer and 5A eprom, and cleaned the 8035 socket and some other corrosion on the board. I can't remember if this issue was present when the board came back from him, because when I first noticed it I just turned up the voltage on the switcher and it went away.
-The problem doesn't really match any of the issues shown on the Brasington tech page (http://www.brasington.org/arcade/tech/dk/) and it doesn't quite match any of the Mike's Arcade repair logs for DK (https://www.mikesarcade.com/arcade/repairs/dkong.html) or DKJR (https://www.mikesarcade.com/arcade/repairs/dkjr.html).
At this point, I'm hoping this exact issue has been encountered and fixed by someone out there, because it's beyond my current skills to diagnose. So, plz halp plz.
-
Could be a corrupted 5B rom.... hard to tell exactly though
-
But are the fireballs staying down?
-
Problem solved. Bad DMA controller (8257 at 7E). Swapped out for a new one (with socket) and all the glitches are gone.
-
Kreygasm
Go good, mate
-
Stream at 3 am?
-
That board was eBay certified working when I had it! That board had 2 huge dirt dauber's nests on it when I first got it. I'm glad you got it working again.