Status: Successfully repaired on 9/28/2020
A Nintendo Donkey Kong board came in for both a capacitor replacement and repair. The board had an issue where everything displayed in blue.
Fortunately Donkey Kong is an early board and is well documented. A little Googleing turned up a thorough list of possible culprits.
This blog pointed me at the PROM at location 2F as the most likely culprit for the blue display. Donkey Kong uses single-wipe sockets which are prone to glitching. Probing the PROM with a logic probe confirmed that several lines weren’t getting signaled, and while probing the lines the full color would blink back on, so the PROM was obviously making a poor connection.
I desoldered the original single-wipe socket and installed a fresh dual-wipe socket.
That resolved the problem – full color was restored.
NOTE: the small amount of vertical blue bleed in this photo was from the Blue Gain being set too high on the JAMMA adapter I was using with this DK board.
All that was left to do now was to remove the old capacitors…
And install fresh, new capacitors.
And that was it for this board. It was fun to work on this classic piece of Nintendo history. These board sets are huge!