My computer was loading into Windows 7, it froze while booting it so I turned the computer off and back on. It turned on but did not get past the bios screen. After about a minute I turned it off again for it to just stop turning on. Odd part was I could see the Ethernet port lights on but hitting the power button did nothing at all (no fan movement, no noise), it even blinked every now and then. There is also no burning smell that I can smell. It was out of the case when this happened and yes everything was plugged in. I also made sure to touch the PSU right before I unplugged it and then again as I was taking it out along with every single time I touched anything.
I also tested with another button and that did nothing.
I know its not the PSU as I have tried this PSU on another computer and it worked fine and then I used another PSU on this one for that not to help. Its not the RAM as I am using it in a spare motherboard I have. Its not the hard drive as I am using that also.
Motherboard is an ASRock A785GXH.
So what do you think I could do to fix this. Also posted on a spare computer, so when I say "this" I am referring to the broken one.
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 once you are finished.
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.
A way that might be easier is to use the main power plug. Working from the back of the plug where the wires come out, use a bare paperclip to short between the green wire and one of the neighboring black wires. That will do the same thing with an installed PSU. It is also an easy way to bypass a questionable case power switch.
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, long single beeps, or series of short beeps indicate a problem with the memory. If you get short beeps verify that the memory is in the appropriate motherboard slots.
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. At this point, if the system doesn't work, it's either the video card or an inadequate PSU. Or rarely - the motherboard's PCIe interface.
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.
No matter what there's a chance it's your CPU. By the rule of averages only probably the MOBO.
CPU is fine. I am reusing it in my spare motherboard. I guess its just shot as no matter what I do nothing seems to be getting anywhere on it. If it helps I put a screw driver against the power on pins and nothing happened, but now I notice when I turn the PSU switch on for either PSU connected to that motherboard the lights seem to dim for a split second.