Power Supply Problem

[apkostka]

Hello,

I bought components for a build last night. Asus M4A87TD EVO Motherboard, Asus 300 case, and I originally had a Rosewill RG430-s12 430W PSU. The green LED indicating power to the motherboard worked, but when I pressed the power button on the fron panel nothing happened. I was unable to get a reading from the PSU on my multimeter, so I went and bought a 550W PSU and hooked it up. Still nothing. Possible problems I see (but you guys and gals will know better than I would):
Soft button on front panel not functioning.
Incorrect wattage (I ran it through several PSU calculators and got anywhere from 205-340W.
Motherboard problem.

Please, please help!

 

[Ubrales]

Rosewill PSUs are not known to be great PSUs. Anyway, a PSU with a higher wattage than required is a good idea.

Check the 8-pins CPU power plug and make sure it is well seated. Same with the 24-pins connector.

What make and model is the new PSU?

 

[apkostka]

The new PSU is a Coolermaster 550W. I didn't see an 8-pin cable. Is it possible that my power supply isn't compatible with my motherboard?

 

[Ubrales]

Cooler Master makes great cases! However, their PSUs are not all that great. Next time get Corsair PSUs.

The CPU power connector is 8-pins or 4-pins in some instances. Compatibility is not the issue.

 

[rogbur22]

Make double sure your system header pins are placed correctly ie the Power LeD, HDD LeD, PWR SW, Reset, etc. if the pins are backwards or anything like reversed power side on ground etc it will not start the machine.

 

[apkostka]

Ok, here's an update: I bought an Antec EA-750 (they didn't have Corsair at my local shop) and now, when I press the power button, the LEDs, CPU fan and PSU fan come on for a split second and then turn off (they don't even go a full rotation). Thoughts?

 

[apkostka]

Wow... I figured out I had the floppy power cable hooked into the chassis fan port. Works fine. Thanks for the help

 

[Ubrales]

Antec is a good PSU like Corsair PSUs.