I was able to find another working motherboard and swapped the VGC chips. Unfortunately it made no difference. The original VGC worked just fine in the new motherboard, but SHR graphics are still corrupted with either VGC in the old motherboard.
Yes, I thought of that as well. VidHD or the ∀2 Analog card look like they would bypass the VGC for video. Unfortunately both are out of stock. I'm still patiently looking for another motherboard to source a good VGC from.
I replaced all 4 standard ram chips with new sockets+ram, but no change to the super hi res graphics. Would finding a replacement VGC be the next step?
I have a Rom 01 IIGS that was recently brought out of storage. 40/80 column text and 8-bit high and double high graphics modes all display fine, but any program that displays the IIGS' native super high-resolution graphics appear corrupted. It does this in both composite and RGB mode. See...