Computer won't switch on

Hi

We have a computer which will not switch on.

Having looked inside the motherboard LED is green when power is supplied. When plugging the power in to the back of the machine the fan spins for a second or so and then it goes off.

I have made sure all power connections are firmly in place on the motherboard, I have removed all external devices which where attached (e.g. mouse, keyboard etc) but still no joy. I have also tried unplugging frontal USB and audio ports etc to see if this makes any difference, but still nothing.

I was hoping someone may be able to offer some advice.

Thanks
Andy

Try removing the power switch connector from the motherboard and with a screwdriver touch the two pins together. If you have power it might just be a dodgy switch.

Although I have seen a machine do similar when the motherboard was broken.

Just to make clear.. the "power switch" connector, not to be confused with the acutal power connector ;)

Sounds like a dead PSU to me - had this happen to my brother's PC. There's enough power to light the LED's but not enough to post. Try a new PSU (or at least a known working one from another machine)

Hi Everyone

Thanks for all your help, will give each suggestion a go.

Cheers
Andy

If you can swap the power supply, that's a good first step. The other thing you could try is to disconnect power to all of the peripherals and see if it tries to boot. If it does, then connect the boot HDD and see if it works. It could be the psu falls over when it has to big a load.

Quote:

---

Originally Posted by TronXP

Just to make clear.. the "power switch" connector, not to be confused with the acutal power connector ;)

---

sorry yeah i'll edit my post!

Check the rear USB for damage.

Rob

I know exactly what this is... it's a case of a dead motherboard I'm afraid the symptoms you describe are the ones of a motherboard shorting... could be some solder somewhere.

By all means grab another PSU from somewhere and try that but I reckon it's the motherboard shorting out.

I used to build PC's and have come across this many many times, especially when someone brought me a machine they had built and had put the motherboard directly into the case without using the mountings.

Quote:

---

Originally Posted by cpjitservices

especially when someone brought me a machine they had built and had put the motherboard directly into the case without using the mountings.

---

That's a site to behold - the crack, the flash, the smoke and the look of sheer dread in the perps face, priceless! (actually, about £150 in my mate's case!)

Actually as luck would have it... I removed the board - screwed in the mountings and screwed the board in PROPERLY into the mountings... LUCKILY the board fired up and was working - How said friend didn't fry the board is uncanny, especially since they tried to power it on over and over and over and over.....

so was just a £30 labour fee to basically rebuild but with mountings this time :rolleyes: