Status: Successfully repaired on 5/3/2020
My friend owned a previously-modded NEC PC Engine Duo that no longer powered on. I agreed to take a look at it for him. There was one heck of an eyesore waiting inside…
Looks like a fine mess of Chong caps, hot glue, leaked electrolytic and a giant physical region switch.
Step One was to remove all the electrolytic caps and the physical region mod.
I scrubbed away the leaky cap’s electrolytic goo from the tainted pads and traces with a fiberglass pen. Then I scrubbed the entire board clean with alcohol and a toothbrush.
Finally I installed replacement caps and a modern region mod.
Note that the SuperCap for maintaining the save game battery is missing in this photo – I was waiting for the part to arrive in the mail at the time.
After this, the Duo powered up fine and functioned perfectly.