Can't power-up

[theodore]

I have a computer which I built myself ( a couple of years ago) and which has always run trouble free. This morning, however, I happened to be using it when suddenly it shut down of it’s own accord. Since then I have been unable to restart it. Appearance-wise, everything looks completely normal apart from one thing, which is that there are no lights at all on the front panel. All other leds are lit up, -the motherboard itself, monitor, keyboard, mouse, the lot. This being the case, it looks to me like the fault is not with the PSU, but I could be mistaken. This is the first time I have ever had a computer actually refuse to power up, so am completely stumped. The computer has not been moved or tampered with in any way.

Motherboard is an Asus Crosshair, with two graphics cards (in SLI), 2 Gb RAM, and a 1000w power supply.

Normally, if a computer has a faulty component, it is still usually possible to switch the machine on, - what happens then is that it will hang on the POST and give error beeps. In my case, however, I cannot even switch the machine on on the first place.

Any ideas or suggestions very welcome. Have already tried diconnecting and reconnecting the leads from the Mobo to the front panel but no luck.

[AWACS]

well.. either you've blown a fuse in the house or the powersuply is history (it also contains some sort of fuse).

good way to verify is using another psu to test if the computer even boots.

[theodore]

The only reason reason why I thought it was not the PSU is because all the leds on the mobo, ( and there are quite a few) are on, - therefore power looks like it is going into the mobo as normal. Would be more than happy to be proved wrong, however!

Will try the PC with a different PSU (as you suggest), as soon as I can get hold of one.

[Crunch]

Faulty switch, maybe?

[Da_Rude_Baboon]

Disconnect all the leads from the PSU to your hardware and then try to 'jump start' your PSU by shorting out the green pin and one of the black pins on your atx connector. If you do a google search there will be guides to this. This will test to see if the PSU is powering up.

You can also use a small flat bladed screw driver to short out the jumpers on the motherboard to start your PC. Disconnect the lead from the cases start button at the motherbaord front panel pin out and touch the pins with the screw driver. If the PC starts you know its your switch.

[AWACS]

hmm my bad... read the first time that the leds were dark :wiz:
though I've had a similar problem but the computer did try to start however never got any further as the 5v rail had failed on the psu.

[theodore]

Hi Rudey,
Thanks for the wiring tip, - it is one I had forgotten about. Anyway, when I short circuit the green wire, (14), with the black (15), nothing happens. I think normally the PSU fan would be activated, so it does look like a faulty PSU after all. Have decided to do nothing more until I have tested the PC with a different one.

[Da_Rude_Baboon]

Your welcome Theodore. :thumb: Sounds like a dodgy PSU if the fans not coming on.

[theodore]

Unplugged all items from the mobo, (except the CPU and CPU fan), and installed new PSU (replaced under warranty). Only difference now is that the PC on/off switch now functions, - but all it does is power up the PSU, (the fan of which is now working). None of the case fans are working, however, and the computer is still not springing to life. All four mobo lights are on, (two red, and two green), plus the blue LCD display on the back panel which reads ‘CPU INIT’. When the ‘LED SW’ button on the back panel is pressed, all the blue lights come on as normal. However, these are the only signs of life, and as the computer will not boot, it looks pretty certain that it is the mobo that has somehow blown. I guess this marks the end of this thread, as there is nothing more to do now except go out and buy a replacement. Am extremely xxxxxx off, as it is an expensive item, awkward to replace, and I thought I was buying the best.

Anyway, thanks to everybody for your interest.

[fivecheebs]

Before you do that, try to get hold of a similar CPU to test the mobo with. A dead CPU will display the same not posing symptoms, although it is probably the mobo at a guess. PSUs can take out other components with them when they die suddenly. Hopefully its not been too destructive.

Good Luck