Check out this site here
for info on what the beeps could mean.
Thanks T_T for taking the time to reply.
As I have the motherboard manual, I was aware the continuous beep could mean a problem with: PSU; Vid card: motherboard, and possibly others.
Having almost completely rebuilt the computer, borrowing parts from my other computer, and by reading other forums, I narrowed it down to a mobo problem.
Turned out to be about the simplest of probs...CMOS battery losing power...I have replaced it just an hour ago and this reply is written on the problem child, booting first off, no beeps other than single POST beep.
That website you referred me to is very detailed and would be really helpful where somone doesn't have their manual...so again many thanks.