Wow. Welcome to the forum, it looks as if you have taken some good diagnostic steps. Only thing right off the top I would add is to remove the cpu fan, blow it out, and put some fresh heat sink grease on. Make sure the core voltage setting is right. You might want to try running it with the side off the case and point a fan at it just to see if the shutdown time increases.
Beyond that, I don't know. I had an old Abit BP6 with celerons (soc 370), it would crash mostly when playing MP3's. I went through all the steps you did (and more), it ended up being a defective motherboard.
I've found the socket 7 AMD's to run a little hot.
Beyond that, I don't know. I had an old Abit BP6 with celerons (soc 370), it would crash mostly when playing MP3's. I went through all the steps you did (and more), it ended up being a defective motherboard.
I've found the socket 7 AMD's to run a little hot.
