The computer was free and having problems with PCI video cards in Windows, so I decided to experiment. I tried flashing an Asus P4S533-MX motherboard BIOS using Aflash.exe. I thought maybe it could work, same SiS 651 chipset. It POSTS and boots, but only with 1 stick of RAM and the CPU fan speed is 100% at all times, hardware monitoring also doesn't work, and it always says "ERROR -- Cannot update ESCD".
It boots disk devices, so I figure no problem, I'll just flash back to stock.
When I try it with AFLASH.EXE, it appears to work, but I get:
Address 00000h expected (20h) real (23h)
Error--Data Compare Failure!
Same thing happens no matter how many times I try. Also tried the DMIFLASH.EXE that came with the Sony update utility, and same thing. Acts like BIOS is write-protected. BIOS chip is identified as an SST49LF020A.
The BIOS is soldered. I can probably un-solder it and reprogram it using a burner, but thought I'd see if anyone has any possible solutions before I go to the trouble.