computer wont start at all!

devil_incarnate

I've got a dell Vostro 430 desktop, which is about 2 years old.

Sometimes I've had to press the on.off button a couple of times, or hold it in for about 15 seconds, for it to start. However, now it isn't starting at all when the button is pressed. No beeps, noise of fans or HDD spinning, nothing at all.

I've tried putting in another power supply, but still the same. Could it be the on.off switch? Or can anyone point me in the right direction of what's wrong please?

I'm a regular poster, but as login and password are on the other machine, I had to re register!

Many thanks

Figment

It could be the switch, but could also be a fault on the motherboard, as on the vast majority if not all modern machines the switching of the power supply is controlled by logic on the motherboard.

DCFC79

You could maybe see if you can get ot the on/off switch to see if it is that, you might end up breaking the front part though.

robmar0se

I would respectfully suggest that the first thing to check is the power button on the front of the desktop.

There are 2 ways to do this - take the front panel off and see if the power switch behind the power button has come loose (sometimes the plastic retaining clips break), and/or short the cable from the power switch where it is attched to 2 pins on the mainboard (this effectively should either turn the desktop on/off) - sorry couldn't find a mainboard layout of yr desktop to be more precise),

To remove the front panel: Remove side panel, and very carefully use a flat blade to unclip front panel.

devil_incarnate

Thanks for your responses, everyone.

I've got the front panel off (good job I didn't have fingernails, or I wouldn't anymore) and the switch seems to be in position. When i press it, I feel it clicking. Its also wired in to a light which shows hard disk activity, so there are a few wires in the bundle.

One of my kids has the same model PC, so I might try taking the switch off that and seeing if that helps. My big fear is that there's a problem with the motherboard.

Anyway thanks again and more comments /suggestions gratefully received!

Toxteth_OGrady

You can try jumping the two PWR header pins that the switch connects to on the motherboard with an insulated flat blade screwdriver to see if the PC starts. That will show whether it's a switch or mobo problem.

robmar0se

Toxteth_OGrady wrote: »

You can try jumping the two PWR header pins that the switch connects to on the motherboard with an insulated flat blade screwdriver to see if the PC starts. That will show whether it's a switch or mobo problem.

Agreed. Follow the two "coloured" wires from the back of the switch to where they are attached to the motherboard, gently lift them off the two pins they are attched to, then as suggested take a small flat screwdriver and touch both pins very carefully, and hold it there for 2-3 seconds to ensure you have "shorted" them. Hopefilly you will hear the fans start up. Fingers crossed!

devil_incarnate

Its not the switch.

I've just tried my switch in the son's PC, and it fires up no problems. (incidentally, I did look to short the wires, but out bof the two coloured wires which went into the back of the switch, they went to different terminals on a 7 pin block, so couldn't short these pins without touching others as well)

So I'm now thinking its back to dell for a new mobo, unless anyone's got any other ideas? Any way to test my mobo?

Thanks again!

Figment

Where did you get the replacement power supply from?

devil_incarnate

Figment

I got it from Maplins. Normally wouldn't buy from there, but wanted something quickly ....

BUT ...

Put the old switch back in, wired up the old power supply again, pressed the switch and after a pause of about 10 seconds the fans started! It was nothing that I haven't done many times over the past few days! Now working as though nothing has happened!

So it looks like an intermittant fault.Any suggestions on how I can track it down, now that the immediate crisis is over?



So

Figment

devil_incarnate wrote: »

Figment

I got it from Maplins. Normally wouldn't buy from there, but wanted something quickly ....

BUT ...

Put the old switch back in, wired up the old power supply again, pressed the switch and after a pause of about 10 seconds the fans started! It was nothing that I haven't done many times over the past few days! Now working as though nothing has happened!

So it looks like an intermittant fault.Any suggestions on how I can track it down, now that the immediate crisis is over?



So

Unless they've changed recently, DELL power supplies/motherboards have custom wiring, so only DELL supplied power supplies work - unless you're prepared to start swapping a few wires around.

It's possible one of the connections wasn't quite made, and by removing and replacing the plug you've solved the problem. Only time will tell.....