iv had this 780i for nearly 2 years and its never missed a beat running 3x gtx285 but the other day i tried to boot my pc ,,, it did nothing no beep no bios screen even the on board reader says nothing just ff tested with i pci test and it said no errors tried diffrent ram and even reset the bios
psu is fine could it be a failed north/south chip or is the board dead was a costly board
Breadboard with just motherboard, CPU & HSF, case speaker, and PSU.
Make sure you plug the CPU power cable in. The system will not boot without it.
I always breadboard a new build. It takes only a few minutes, and you know you are putting good parts in the case.
You can turn on the PC by momentarily shorting the two pins that the case power switch goes to. You should hear a series of long, single beeps indicating memory problems. Silence indicates a problem with (in most likely order) the PSU, motherboard, or CPU. Remember, at this time, you do not have a graphics card installed so the load on your PSU will be reduced.
If no beeps: Running fans and drives and motherboard LED's do not necessarily indicate a good PSU. In the absence of a single short beep, they also do not indicate that the system is booting.
At this point, you can sort of check the PSU. Try to borrow a known good PSU of around 550 - 600 watts. That will power just about any system with a single GPU. If you cannot do that, use a DMM to measure the voltages. Measure between the colored wires and either chassis ground or the black wires. Yellow wires should be 12 volts. Red wires: +5 volts, orange wires: +3.3 volts, blue wire : -12 volts, violet wire: 5 volts always on. Tolerances are +/- 5% except for the -12 volts which is +/- 10%.
The gray wire is really important. It should go from 0 to +5 volts when you turn the PSU on with the case switch. CPU needs this signal to boot.
This checks the PSU under no load conditions, so it is not completely reliable. But if it can not pass this, it is dead. Then repeat the checks with the PSU plugged into the computer to put a load on the PSU.
If the system beeps:
If it looks like the PSU is good, install a memory stick. Boot. Beep pattern should change to one long and several short beeps indicating a missing graphics card.
Silence or long single beeps indicate a problem with the memory.
Insert the video card and connect any necessary PCIe power connectors. Boot. At this point, the system should POST successfully (a single short beep). Notice that you do not need keyboard, mouse, monitor, or drives to successfully POST.
Now start connecting the rest of the devices starting with the monitor, then keyboard and mouse, then the rest of the devices, testing after each step. It's possible that you can pass the POST with a defective video card. The POST routines can only check the video interface. It cannot check the internal parts of the video card.
i had 2 of the 3 cards out so i could see the post i also tried swaping the gpu's around
the post dosent do the system test the fans run the post stays on ff normaly it would run thru the numbers ie " 12-24-36-L1-FF "beep then boot
it is not running the system test im sure
the system was working fine the day-week-month before
iv since tested the system components on a frends pc and found no faults and after spending around an hour on the phone to xfx and them blaming other components and saying my water cooling must have leaked "i dont have water cooling !!!!!!" they then suggested i contact the retailer and send it back worst help desk iv ever had the misfortune of speaking to very dumb indeed