Reply 40 of 50, by froller
Continuing my adventures with LS-486e Rev:D
I've managed to replace fried power BJT with new TIP127 and got 3.3V and mobo started with Am5x86-P75-133ADZ and 2x4MB FPM RAM.
Then I decided to check if it supports EDO and installed 2x64MB EDO and mobo started and checked all 128MB and asked for floppy.
I turned everything off to tie up floppy and... nothing went up. Mobo refused to start.
Replacing EDO with FPM also didn't help. Removing memory lead to POST beeps 'bout missing memory. But now it refuses to start either with RAM or without. With RAM it doesn't even get to video initialization so no beeping 'bout missing VGA.
Don't know if it matters but EDO RAM has its own 3.3V regulators onboard and I checked RAM chips are powered by 3.3V.
Did I run into some sort of electrical incompatibility of newer RAM?
Virus check complete. All viruses are working properly.