Just in case anyone has this problem:
Intel P4 system with MSI mainboard – new case +PSU.
HD attached to mainboard correctly, power leads OK, but HD won’t spin. IDE cable removed and drive spins. HD not recognised on BIOS. HD functional in another PC.
rest of system looked ok
Checked wiring carefully
Thought mainboard IDE controller failed
BUT eventually realised that DVD drive cable was attached incorrectly. When this was corrected both drives seen on BIOS and everything worked normally
