I am upgrading my system to a Gigabyte ep45-ud3p motherboard and have run into an issue with the power supply. The case is an Ultra Dragon with Ultra 400w power supply of about 2003 vintage. My problem is that the main board power connector is 24 pin and the psu is 20 pin. There is also a 4 pin connector from the psu. I have plugged the 20 pin in and when powered the drives and lights on the MB come on but no cpu fan and no boot. I assume that it is missing the power from the 4 empty pins. Does the 4 pin connector fill these empty pins or do I have to get a new power supply? Thanks for the help.
I'd recommend a new PSU, however we need to know the rest of your system specs. This way we can determine what wattage PSU for you (remember Overkill is fine for PSU's, too low a wattage is bad). But a solid 650W should last a while (unless you are using X-fired 4570's, or SLI'd 280's).
The separate 4-pin cable is for CPU power; its connector is not near the 24-pin connector. It will be close to the CPU socket.
That Ultra PSU, especially that age, is probably not safe to use in a new rig. You can pick up an Antec Earthwatts 500 pretty cheap now at newegg.
thanks for the replies. I was afraid of that. the complete system is:
2x2gb Corsair Dominator 1066 Ram
2 250GB Maxtor SATA drives
ASUS EAH4350 SILENT/DI/512MD2 Radeon HD 4350 Video Card
am currently looking at PC Power & Cooling S61EPS 610W