I bought a PC Engine “as is” off eBay with the hopes of repairing it for personal use. I opened it up, did a cap replacement, replaced the (bad) fuse, and reflowed the power jack. After all this, I turned it on with the SSDS3 (because I didn’t have a HuCard) and this is what I saw:
So I put this on the back burner for a few weeks. I got myself a tester HuCard from a generous friend:
I took a final stab at it and removed the RF modulator for good measure:
I then noticed that the HuC6270 looked like it had been messed with/corroded. I reflowed that side of the chip, then tested for continuity. I found 2 pins that weren’t connected; it looked like the pads underneath the pins had been damaged. I used some kynar to connect the pins to the nearby vias:
I hooked up a jank RGB connection to test it out:
It worked! So it looked like fixing those 2 pins solved the problem. I closed it back up and tested it with the SSDS3:
I’m happy with how this turned out, I was afraid I would have to give up and get another system, but luckily this was a success.