Harmy said:

Much appreciated guys - it seems the returning of the broken motherboard won't work out (they found that some of the pins on the CPU bed were slightly bent and tey said I must have done it and gave it as a reason to not refund me for the mobo, even though I'm convinced it can't possibly be what was causing the problems, which didn't appear until I put in the additional RAM), so this will help a little to cover the cost of the new one.

You're most welcome.

And I don't know where or who you're getting your motherboard from but that sounds like a pretty shady reason to not replace it. If it worked at one time and all you did was add RAM, you didn't touch the bed after that. Anyway, any reputable dealer would only need to ship the board back to the manufacturer and get a credit - it's not like they're losing money on it. (sigh)