Computer not switching on

Centipeed

My computer was working fine last night. This morning I press the power button, and the green light below the power button switches on, but everything else stays the same. Aside from the green power light, everything stays in the same state it is is when the computer is off: No whirring fans, no flashing lights, no beeps and boops, nothing.

The two orange lights on the motherboard, which stay on whenever the computer is getting power from the mains, are still on. They still work as always, and no other lights on the motherboard are either on or off when they're supposed to be something else.

I've tried pressing the power button on the motherboard itself, since I have one and thought the main power button might be faulty. No go. I've tried re-sseating the ram and unplugging various fans and checking the power cables on the harddrive, DVD drives and the graphics card. All of the do shit-all.

The green power light that I originally mentioned has also stopped working, so when you press the power button, not even that turns on.

Have any of you experienced this exact problem, and if so, what did you do to fix it/what is the most likely cause?

nuclearalchemist

I don't have experience with that exact problem, but it sounds like a power issue (which you have probably figured out on your own). Unfortunately, if its not even posting or anything, you really would either need to stick a voltmeter into the various parts of the PSU to figure out if its working, or try to figure some other way to see if the board is actually getting power. If the motherboard is actually getting power, then its a power issue with your motherboard.

Basically, somewhere it is a power problem, because otherwise the machine would at least post.

Dunadan019

the overvoltage protection in your powersupply may have been triggered (by some surge or power outage). I think you have to turn it off and on (the physical switch at the back) twice to get it to work again.

Taranis

Does the fan on the PSU work? I would try changing power strips/surge protectors if you're using one. The LED that turns green when you press the power button, is that the LED on the PSU or the case? If it's the PSU I'd say it's the PSU that's the problem, if not it could be either that or your mobo or both.

Erandus

See if you can yank a PSU out of a friend's PC (make sure the wattage is similar or higher than yours) and try it briefly in yours.

Did you get storms overnight or anything?

Dunadan019

specifically:

http://www.formfactors.org/developer%5Cspecs%5CATX_ATX12V_PS_1_1.pdf

Paragraph 3.3.7:

If the power supply latches into a shutdown state because of a fault condition on its outputs, the power supply shall return to normal operation only after the fault has been removed and the PS_ON# (or AC input) has been cycled OFF/ON with a minimum OFF time of 1 second.

If that doesn't work, you probably need a new power supply.

Centipeed

I've tried the switch on the back of the power supply several times. No go.

The green light I mentioned was the light on the case, not on the power supply.

The power supply is actually the second newest component in the whole bunch (The newest being the graphics card), since my old one died on me, and I bought this new one. It's a high quality power supply, and is a replacement of the old one, which lasted five years or so.

The motherboard, however, was bought when I first built it, quite a few years ago. Is it likely to be a motherboard issue, given that the two orange lights that are normally switched on are still switched on?

Taranis

Centipeed wrote: »

I've tried the switch on the back of the power supply several times. No go.

The green light I mentioned was the light on the case, not on the power supply.

The power supply is actually the second newest component in the whole bunch (The newest being the graphics card), since my old one died on me, and I bought this new one. It's a high quality power supply, and is a replacement of the old one, which lasted five years or so.

The motherboard, however, was bought when I first built it, quite a few years ago. Is it likely to be a motherboard issue, given that the two orange lights that are normally switched on are still switched on?

A power surge protector/power strip could be cause, it's doubtful but if you're using one I'd recommend switching it. Try to find another PSU of a similar wattage to use in your computer as suggested before. I wouldn't try using the PSU in a different computer since if that's what's at fault here it could short out something in another computer. Failing that I'd send in both your motherboard and PSU if they're both under warranty.

alabaster

Try unplugging it from the wall, holding down the power button for 15 seconds, and then plugging it back in. I've had to do that on both Dell and Gateway workstations in the past. Not sure if it will work here.