Excellent news, congrats. Are you able to edit the post title? What would you say to add some short note in the end of title that issue was solved and root cause was L2 cache, including also Mainboard model numer. This will help others in the future with similar problem.

Which CPU have you put on that board? Is it with WT or WB cache? Do you have some other CPU to try?

Do LEDs on keyboard lights up when i.e. Caps Lock is pressed? Maybe there is some issue with keyboard or keyboard controller on the Mainboard?

100% that PC was a 386, that I remember for sure. And 100% I played Duke Nukem 3D on it. Unfortunately I agree with imi , that Duke Nukem 3D is not playable on 386 class rig. However maybe it's just confusion in name of the game, because there are Duke Nukem 1 and Duke Nukem 2, the 2D predecessors, …

I'm very impressed with such a great job you did to resurrect this board back to life. And moreover I'm really happy to see you sharing your story here. This is really a huge inspiration for me to not give up with all fights to have my main boards back to live. Thank you very much for your post. You …

3)WD42C22A Old hdd controller i believe.Not tested because i only have IDE drives and floppy conttector is not soldered.Are there any way to test it? This controller is intended to be used with MFM hard disk drives, which will use both a 34-pin control cable and a 20-pin data cable. This controller …