Device fails to start or initialize properly.
Device fails to start or initialize properly.
I considered taking the BIOS chip out and checking it on another machine to verify if it matches a new one from the internet. If you're working with older PCs, that’s often how you resolve BIOS problems—sometimes a 'chip clip' is needed for soldered boards. I’m not sure what caused it, but it seems like a corrupt BIOS. The board wasn’t in the case until a few years back and was just sitting on cardboard in the basement corner. It’s still a mystery; I don’t have any 478 CPUs.
I'm still working on organizing my desk area. It looks like nothing is progressing today, so I'll focus on finishing the BIOS floppy before testing it.
I wrapped up the BIOS floppy, connected it and ran tests. Nothing worked, but I discovered an issue: the board is reporting a failed CPU test. It seems there are two possible causes—either the CPU itself is faulty or the VRM caps are damaged and need replacement. I suspect the overheating northbridge is also contributing to the shutdown. After the first boot, it attempted a boot and then shut down. Upon inspection, the northbridge was clearly hot. I have two potential problems: a defective CPU or worn VRM caps. The overheating northbridge issue appears straightforward to address by replacing the tubing and directing water flow. The remaining challenge is harder to diagnose since I don’t have another compatible 478 socket CPU available. Do you have a suitable 478 model I could borrow?