New build will not power up...

[Carver_inc]

I have the PSU plugged in, both power cords are plugged in...2x4 12v power and 2x12 Main Power...
Right now I have no light on mobo, nothing..

If I took the PSU out and plugged it into the wall while hooked up to nothing and turn it on, should the fans on it spin?


Corsair 550w psu, gigabyte GA-P55A-UD3, i5 760, hd 5870....

 

[mfenn]

No, the PSU will not power up on its own normally. You have to jump the green wire to a black wire on the ATX connector to cause it to power up (with nothing else plugged in!).

Other things to try:
- Make sure the PCIe power connectors are plugged into the 5870.
- If the PSU has a switch on the back, make sure that it is plugged in.
- Take the PSU, mobo, CPU, memory, and GPU out of the case and try it there. This will avoid any grounding or shorting issues. Use a screwdriver or car key to jump the power switch pins.

 

[Carver_inc]

Ok, I used a paperclip to jump the green and black wires and the fan spins..
I took the video card out, and left everything else plugged in, still no light on mobo, no cpu fan spin...

Gonna take it all out of the case, see if its a grounding/short issue... update coming..

oh and Thank you for the help!

 

[Carver_inc]

Took PSU, mobo, out of case. Plugged in both power connectors, no light on mobo, no cpu fan spin or PSU fan spin...

Would my heatsink cause this problem...Im pretty sure its installed correctly, but for the sake of troubleshooting, should I take it off and reseat?

 

[BoomerD]

Took PSU, mobo, out of case. Plugged in both power connectors, no light on mobo, no cpu fan spin or PSU fan spin...

Would my heatsink cause this problem...Im pretty sure its installed correctly, but for the sake of troubleshooting, should I take it off and reseat?

The HSF shouldn't cause the problem at all. Are you SURE you have everything plugged in correctly?

Do you have both the 24 pin ATX plug and the ATX_12V_2X4 plugs in properly?
Failure to connect the ATX_12V_2X4 plug will prevent the computer from booting in most cases.

Make sure you have your video card plugged in properly as well. IIRC, the 5850 takes 2 PCI-E connectors.
Troubleshooting tips start on page 112 of your manual:
http://download.gigabyte.us/FileList/Manual/mb_manual_ga-p55-ud3_e.pdf

It's not unheard of to get a board that's DOA, but be sure to try to troubleshoot it first before asking for an RMA.

From reading what you've done, I suspect a DOA board...but due diligence says to double and triple check everything.

 

[mfenn]

Took PSU, mobo, out of case. Plugged in both power connectors, no light on mobo, no cpu fan spin or PSU fan spin...

Would my heatsink cause this problem...Im pretty sure its installed correctly, but for the sake of troubleshooting, should I take it off and reseat?

Like Boomer said, I doubt it is the heatsink, but reseating it won't hurt. If you have multiple memory modules, you can also try with just one or the other.

It might also be helpful if you list every wire that you currently have plugged into them mobo and GPU, so that we can see if you missed anything.

 

[wirelessenabled]

I had the same problem on a new build today.

I cleared the CMOS and it started up fine on the next try

 

[MagnusTheBrewer]

Double check your case connectors. Look for the embossed triangle for correct orientation to pin one. Do not depend on the cable labels.

 

[BoomerD]

He got it fixed and explains what happened here:

http://forums.anandtech.com/showthread.php?t=2131057