I've just built a system for a friend (spec at the bottom of this message). We forgot to order a DVD drive, so thought we would use one from an old machine.
I first tried booting without the DVD drive attached and everything was fine - we got into BIOS ok, all components (CPU, RAM, hard drive) were correctly identified and the machine was running at a reasonable temperature. All good so far.
I then powered down the machine and connected the old DVD drive - at this point the system refused to power on (i.e. the fans wouldn't start and no LEDs lit up). Strangely, disconnecting the drive has failed to resolve the issue - pressing the power switch on the front of the machine makes the PSU's fan move a tiny amount before stopping, whether the DVD drive is connected or not.
To me it sounds like a faulty PSU, but it seems odd that the computer booted into BIOS perfectly the first time around. Is it possible for a faulty DVD drive to somehow knock out the PSU or (please please no!) the motherboard?
Many thanks - here's the spec:
Asus P8P67 LE R3 P67 Socket 1155 8 Channel HD Audio ATX Motherboard
Intel Core i3 540 3.06GHz Socket 1155 4MB L3 Cache processor
MSI HD 4670 1GB GDDR3 Graphics card
Corsair 4GB (2x2GB) DDR3 1600MHz/PC3-12800 XMS3 memory
Be Quiet 530W Pure Power PSU
Samsung HD103SJ Spinpoint F3 1TB Hard Drive