Is it dead (again) jim?

Well I guess I spoke too soon.

I replaced my PSU and my PC was running like a champ again for 2 days - no cold boot issues.

I also decided to buy a new vid card. Then this afternoon, after a quick round of gaming to test the new card, I decide to reboot. The system, starts to POST but the ASUS logo goes from orange text on black . to black logo on an orange screen. I wait 5 minutes .. nothing happens. I restart the machine.

All the lights, keyboard and HD leds blink appropriately, the monitor looks for a signal and gets nothing and goes into standby mode (monitor is ok). no video, no POST . I try again, and just all the fans, USB, HDDs, DVD are going but no video signal.

I check all the connections and they are secure. I try again, no dice. I swap out the new video card for the new one.. which was working 4 hours before. also has no signal. I have tried different PCI-E slots as well.

I have tried both a jumper and battery pop CMOS reset. It doesnt help. I am going to try to leave the battery unplugged and no current to the CPU overnight because I find sometimes CMOS doesnt clear quickly.

I cant understand what went wrong. Is the motherboard dead - perhaps that was the root cause all along, not the PSU? Perhaps it is possible the new PSU (Corsair HX650) is bad .. yet it seems to power everything - short test was fine.

/back the repair gerbil wheel
/sigh

FR

Work through our standard checklist and troubleshooting thread:
http://www.tomshardware.com/forum/ [...] t-problems
I mean work through, not just read over it.

Breadboard - that will isolate any kind of case problem.
http://www.tomshardware.com/forum/ [...] adboarding

The breadboarding thread has a paragraph about how to build and test a PC in stages.

Breadboard with just motherboard, CPU & HSF, case speaker, and PSU. You do have a case speaker installed, right? If not, you really, really need one. If your case or motherboard didn't come with a system speaker, you can buy one here:
http://www.cwc-group.com/casp.html

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.

If no beeps:
At this point, you can sort of check the PSU. Try to borrow a known good PSU. 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.

You can turn on the PSU by completely disconnecting the PSU and using a paperclip or jumper wire to short the green wire to one of the neighboring black wires.
http://www.youtube.com/watch?v=5FW [...] tube_gdata

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.