Shortcircuit between Case and Motherboard

[jconblack]

Hello everybody, i have a problem with my new homebuilt pc. The system does not boot when mounted on the case, but it starts normally breadboarding (spelling?), with the motherboard with the cpu and the memory, out of the case.
The motherboard has 9 screw holes, all of them used to attach to the case. All the standoffs needed are placed in the case.

The motherboard is a gigabyte ga-890gpa-ud3h, the case an Antec Two Thousand. The psu is an XFX XXX Edition 650W.

What should i do? replace the case? replace the motherboard?

Thanks.

 

[Paperdoc]

1. Are you absolutely sure that the standoffs are located ONLY exactly where the mobo mounting holes are?
2. Did you place insulating washers between the mobo and the standoffs? You should NOT do that - those mounting points are INTENDED to be grounded to the case through the standoffs.
3. Any other odd pieces of metal or bent edges in the case that might be making contact?
4. Examine carefully the metal shield plate that fits around the rear connectors that stick out the back of the case. I once found that, as I installed mine, I had a couple of springy metal fingers stuck INSIDE a connection port, rather than beside it.
5. If it still fails inside the case, what else do you observe? Does it do absolutely nothing when you push the front panel power button? Or, does it "start" for a second or two then quit? How did you start it when "breadboarding" - short out two pins on the front panel connector port? When in the case, disconnect the wires from the front panel power switch and short them out again: does it start up that way? In fact, check to be sure you have the front panel switch leads all connected properly.