Hi all, I have a perplexing issue with an NES that I RGB modded with Tim Worthington's RGB Mod board. The board revision is 2412, NESRGB42. I have fully re-capped the NES and installed a new AV power module by Merlin Shaw with a Genesis 2 port for RGB. Everything has been working flawlessly, but recently it started locking up with certain games. Most notably, Alien 3 while playing. It can be a few mins and the screen just freezes. Sometimes the screen goes black, sometimes it freezes everything like the game is paused. Contra Force boots to the loading screen and locks up; you cannot press start. It freezes every time. What’s strange is I can play many other games without issue. No graphical artifacts are present. I have run my oscilloscope over the test points here https://wiki.console5.com/wiki/File:NES ... eforms.png and noticed proper wave forms on the PPU while running Super Mario and it never locks up. However, running one of the games that locks up, it seems like the CPU stops sending data on AD0 - AD7. Running these games on an un-modded system all works as it should, and these same cartridges never hang. Could this be an issue with the RGB mod or could it be a CPU going bad or faulty RAM? I have tested voltage and it's 5v solid, tried multiple adapters. The NES RGB board is using power from the main board. I did not wire the extra 5v regulator as the one on the new power board is much beefier and supports it without voltage drop. I searched the forum and have not come across this exact issue. If someone can point me in the right direction of what else I can test to rule out the system itself, I would greatly appreciate it.
Statistics: Posted by dhauf — Fri Jan 24, 2025 1:44 pm — Replies 0 — Views 9