Win98SE, it was the primary home os at the time. BTW I think I might have killed the motherboard 😒
I set it all up and gave it a quick test, it worked on first try, cpu detected as celeron 500 and everything. I tried various ram sticks till I found the combination I liked, that being 3x64mb pc100 sticks, so gave it quite a few reboots and had no issues. But then I guess I did something unnecessary. I had set the cpu speed manually from the dip switches to 7.5x66. I thought it would be nice to enable the JumperFree mode so I can tinker with it from the bios and maybe try to OC. So I moved all dip switches to off position and moved the JEN jumper to the jumperfree enable position. When I turned it on, got no boot. I thought, huh, guess it wont work for some reason, ok then, lets go back to how it was. So I moved the dip switches to 7.5x66 again and the JEN jumper to disable jumperfree mode, exactly how it was initially. Turned it on, and got smoke!

I think it came from this Q1 component, in fact I think I saw it briefly flash before I managed to switch it off. Any idea what happened and if its fixable?
P.S. Figured out the cause was a bad power supply re-cap job with fake capacitors. I will re-cap the psu properly now, but about the motherboard, I need to replace this... transistor? And hope nothing else got fried. Would help me out a lot of any of you guys happen to have a P3B-F and can tell me what this transistor is exactly so I can order a replacement. This one bubbled-up in the middle so cant read the markings.
P.S. 2 sadly that component is unreadable, I will have to rely on someone being able to tell me what it was supposed to be 😒
