Newly built computer won't turn on.

[Tartanfury]

Long time lurker, first time poster. I decided to build my first computer this summer and started today. It's a M4A89GTD Pro with AMD Phenom II inside an Antec Sonata III case, which comes with its own 500w power supply. I'm also using a Sapphire 5770, 2x2 GB Crucial RAM. 1TB Western Digital as well.

I put it together following the mobo manual, but when I try to turn it on, it won't even power on. No lights, no sound, nothing. It's as if there's no power going into it. It's plugged in, the PWR and RESET cables are in, the 24 pin is in as well as the 8 pin 12V. The video card is plugged in. Is there any detail I could be forgetting? If I'm leaving out important information, let me know and I'll fill you in on it.

Thanks in advance!

 

[ahnilated]

Did you make sure the power supply, power switch was turned on? Is there any LED's lit up on the motherboard?

 

[Tartanfury]

The power supply switch is in the on position on the outside. There is one LED on as far as I can tell on the mobo; it's the standby power LED.

 

[adaman2576]

Check the polarity on the power switch wire running to the mother board. Should only be a two pin connection try flipping it around.

 

[Tartanfury]

Reversing the polarity of the POWER SW did not work, I don't think. There is something new I noticed, though. When I push the power button, there are two small blue lights that light up in the front panel very briefly. If I push the power again, they don't reappear. They only reappear when I turn off the system then turn it back on then press the power button.

 

[adaman2576]

Do you have another power supply laying around or one you can borrow to test in your system?