Glad to hear you solved your issue. Like I said something wasn’t making a connection on mine. I always reflow the chips on repairs. The solder is old and reflowing rejuvenates. You must have had a pin or two on the Konami custom that was flaky. Good job
I did replace some other ICs (don’t remember which) to get it working initially. Shortly after I got it working the purple hue (discolored graphics) appear randomly and disappear after turning it off. I would try to find the schematics. It could be something in line with the 273s or potentially...
I believe I had some trace or vias(can’t remember)damage around the 273s (on the top side). Try applying little finger pressure to the area while it’s on. I found my fault by accident. I noticed when I pushed down slightly it would fix or make worse. Hope that helps
So I actually had this same exact issue. It ended up being the traces, or soldering around the two 74LS273 chips. I just replace the 273s and made sure all the traces had continuity. Mine works fine now and never had that problem again. Hope this helps
@Derick2k I can see that you’re going to be selling these but will it be released later for open source? I don’t mind paying for one I’m just asking. You can add me to your list for one.