Monitor won't come on, VGA lite on, no beeps...


Aug 31, 2011
OK so I finished building my PC and I'm having a problem. I turned the computer on once it was all finished and it worked fine, went to bios(didn't make any changes). I then installed windows, then just did some stuff online.

After about 30-40mins I turned it off and then 2 mins later tried to turn it back on and it the monitor won't come on,it won't beep,and sometimes it cycles through the VGA,CPU, and DRAM LED, more commonly the VGA is the only one lit.

If I wait a while and mess with stuff like unseating the graphics card and put it back in then it'll work (It's not that it's not seated right, I push it in hard,hear the snap and check to make sure it's locked in and screwed). But EVERY time I get it to work it'll only work until I turn it off. When I try to turn it back on, same problem.

I just don't get how it'll work fine and then just turning it off and then trying to turn it back on can make it stop working.

My build.
P8 P67 pro rev 3.1 motherboard
i5 2500k
GTX 470 (works in my other PC)
Performance 2gb ram
Corsair GS 700w PSU

Any help would be greatly appreciated.
Try unplugging the PSU power cord after you shut down. Wait a few minutes, plug it back in, then try to turn on the system. If the system now works, you have a glitchy PSU.

Work systematically through our standard checklist and troubleshooting thread:
I mean work through, not just read over it. We spent a lot of time on this. It should find most of the problems.

If no luck, continue.
The following is an expansion of my troubleshooting tips in the breadboarding link in the "Cannot boot" thread.

I have tested the following beep patterns on Gigabyte, eVGA, and ECS motherboards. Other BIOS' may be different, but they all use a single short beep for a successful POST.

Breadboard - that will help isolate any kind of case problem you might have.

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 (standby power supply): 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.

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.


Aug 31, 2011
Thanks for the advice, I'll try taking the PSU back and getting a new one.

Also just to add this incase it makes a difference. When it's working I can go to the windows start button and hit restart and it'll restart just fine, it's only if I hit shutdown and then try to turn it back on does it not work.