I upgraded my MB and CPU to Gigabyte GA-MA785GM-US2H (BIOS Award F3) and Phenom II X2 550, using 2 x 2 GB dual channel DDR II Mushkin memory.
Started the computer without reinstalling the XP (SP 3). The computer passes the POST and boots.
Deleted some unused old drivers from Device Manager and installed the new drivers form the DVD coming with the MB. The computer functions properly. However, there is no beep when the computer boots and no LED on the MB. Is this normal?
First and most obvious question: are you sure you properly connected the case speaker plug to the MOBO's front panel header? Do you have a case speaker? A lot of people operate under the misaprehension that the 'diagnostic beeps' should come through the speakers attached to their sound-card/chip - not so! Your three hundred dollar Altec-Lansings won't do you any good here - you have to have a case speaker attached to the front panel header...
and no LED on the MB
There are no LEDs on that motherboard, that I am aware of...