might be worth resetting the motherboard - normally there is a jumper next to the onboard battery ? (read the book - often you need to unplug mains and battery first or you can fry things !!!!)
ram chips might need to be in slots 1 and 3 rather than 1 and 2 (assuming you are sticking in two slots) - some m/b can be a bit particular.
is there an onboard video - can you get anything from it using that ?
is there mention in the book about beeps - "one long and two short for no ram" for example ?
sacrifice a small furry critter to your favourite deity.
swear at it a lot (the computer not the deity - or we could be back to frying things again
).
good luck !