Previously I "home-brew" 29-wire modded my v1.0 Xbox with an old PC BIOS. Worked great for many years, but I thought I'd use some of the features of the SmartXX OPX 2MB, so I bought one.
I carefully cut only my wires flush to their previous solder points (except backside D0). The LPC solder was carefully sucked out (reverse side of the low-power iron) so the pinheader was installed. After connecting the shortest D0 length (non-braided) to the OPX, it was put on the LPC pins and turned on. Frags....
Original BIOS also frags... unsoldered D0, unplugged OPX, box still frags.
After examining the work under a microscope, I and another engineer can find no faults. GND/3.3/5V are present on the LPC. Carefully removing just the plastic of the pinheader showed no flaws either. Removed the pins; still frags.
Filled the LPC with solder & tried the OPX as direct-wire in a last ditch effort, still frags. Also had tried spray flux-cleaner. Board looks brand new, just still frags...
Minus the modchip, D0 rises to 5V briefly (during the 2 shutdowns before frag) only to fall to GND (so the original BIOS hasn't a chance of working, obviously not the LPC BIOS either. Once it stayed at 5V, but still fragged, it only did that once. Topside D0, samething.
Only thing I haven't tried is attaching my digital logic analyzer to see if there is CLK (a heartbeat) on the LPC or PLL chip to see if this box has a heartbeat left at all in it.
Was a nice v1.0 with fan on GPU, least it has a good Phillips DVD. I ordered (4x what I paid for the 2MB OPX) an unknown version used xbox; I'll have it on Wednesday (considering softmod here, after this disaster, even tho I bought the OPX 2MB, Blue LCD, & XCM crystal case). I'll probably use the case at least.
Any ideas welcome. My OPX made it to USA from Canada. Even tho low watt iron was used, I think this board is toast. Concerned of OPX condition too. I think boxes with LPC solder should just be quick soldered with wires & the pinheader belongs in the trash. BTW, tho it is covered on the forum, the SmartXX website/CD doesn't show the LPC wire connect method.