Hello

i own a rather uncommon Mitsubishi Computer from about 1999, it sports 256mb of PC100 SDRAM a Slot 1 500Mhz Pentium 3 Processor,
and unfortunately a very very dead motherboard

some insight into its past, it was used in a School IT lesson Demonstration as a "whats inside a PC" exhibit, at the time it had been badly tortured by students with sticky fingers, luckily it escaped with a damaged 1.44mb FDD, a slashed front panel harness and a Missing capacitor, i located the top cover to this computer and rescued it along with a Dell Optiplex GX110.

when i got it home i set about replacing the slashed harness with one dug out of a Scrap AMD Athlon PC and a Floppy drive from another generic school PC. the bezels didn't match but not much could be done about it. stupidly i pushed the two legs of the remains of the capacitor together so they would make contact, BAD IDEA!

after hours of toiling around i fixed it up by installing a jumper onto the configuration pins on the "normal" mode (pins 1 and 2),

sucess! it Fired up immediately and POSTed without issue, it loaded into windows 98 and stayed that way up until mid 2020

the height of the pandemic caused me to spend more time playing around with PCs, unfortunately i had lost 4 machines during this time (a SFF dell, an orange Imac and a HP laptop) disaster struck and the Mitsubishi Stopped POSTing, i tried everything in my power and eventually the PSU had also died from old age,

this leads up until today with thanks to some folks on discord i had determined that the capacitor i had shorted probably caused this death, i was skeptical at the CPUs alive state, and removed the jumper to set the board into recovery mode (no jumper) to my amazement, the system beeped! proving the CPU was alive and well and executing code, along with the north and southbridge chips, this left me with a potential short on the Bus as the Northbridge does appear to be heating up more than normal.

going around the board with my finger revealed the Intel NIC chip (an Intel SB82558B L9091H34 SL2P4) was getting EXTREMELY hot, no matter if the PC was turned on and running or in standby mode. it was HOT until you removed the Power completely, the Power LED also flashes for a second and goes out again after the system is turned on,

this leads me here, what can i do with this system? is it safe to completely remove the Chip? does the PC need it to POST? where can i find a replacement chip?

i am also uncomfortable repairing the system myself due to its rarity, so i will be asking a local technician to remove and swap chips,

motherboard model is an AMC E139761 NLX which is a derivative of an intel board of the same model, replacements are expensive and thrus not an option but a couple do come without onboard LAN,

attached is photographs of the computer, the NIC chip and the shorted cap in question.

i do hope i can fix this machine as its very sentimental.