What I am trying to have you check is if your PCI-E slot is bad or if your motherboard is shorting out to the computer case where it is not supposed to be shorted out.
I suggest for the purpose of this test that you attempt to rebuild your computer system outside of the computer case.
This means gutting the computer tower so everything is hooked up minus the computer tower.
You can leave the PSU in the tower if the cables are long enough to reach the motherboard.
Make sure you ground your self first to discharge any static electricity your body may have stored up, before touching anything inside the computer case, touching a cold water pipe that is grounded to Earth ground should be good enough to discharge static electricity. Try to avoid working in a carpeted floor area, because this increases the risk of static electricity build up.
The motherboard should be placed on a table top where it does not have any contact with any METAL objects that might short out the motherboard.
The video card won't be totally secure without the mounting bracket in the computer case slot so be careful that it is secure in the first slot securely.
In case you are asking what is the point of this procedure, it is being suggested to see if your motherboard was somehow shorting out to the computer case somewhere where it shouldn't be.
All your hardware will work just fine minus the computer case.
Connect everything just as it was inside the computer case, if any hardware besides the motherboard can be connected to the motherboard without removing it from the case, feel free to leave it in the case and connect the data cables and power harnesses for the hard drive and optical drives.
You might have a slight problem with the motherboard to case wires that go to the power switch, HDD LED and power LED, if this is the case, carefully try removing the towers front panel circuit board which these wires run to, so they can reach the motherboard.
Try booting up the system up once you have everything connected up correctly and have rechecked everything to be sure everything is correctly connected where it should be.
Please let me know if the computer boots up like it is supposed to.
If it does, you now know your motherboard was shorted out to the computer case where it was not supposed to be.
If this fails, I am not out of ideas yet, so please hang in there.
Edited by MrBruce1959, 20 July 2011 - 01:38 PM.