No Power

[greshoff]

My PC has suddenly stopped powering up. I have checked the PSU with a paperclip and it seems to be OK, fan starts up. Checked the switch and reset connections to motherboard and they seem OK. What else can I do to trouble shoot the issue?
Thanks

[kalniel]

My PC has suddenly stopped powering up. I have checked the PSU with a paperclip and it seems to be OK, fan starts up. Checked the switch and reset connections to motherboard and they seem OK. What else can I do to trouble shoot the issue?
Thanks

Remove as many peripherals/components as you can and see how far it gets - once you can get the motherboard initialising you should be able to see if it throws any error codes/beeps/warning leds - see your manual for details.

[greshoff]

If I switched off the PSU removed the switch cable from motherboard the put a paperclip between the two terminals then switched on the PSU this would determine whether the case switch is faulty. Is this OK to do?

[kalniel]

The PSU might need the connection to be made when it was turned on rather than before - I don't know how soft starts are implemented.

[peterb]

Is there an LED illuminated with the PSU connected and plugged in? (Check the motherboard manual to see where it is - or if it is fitted, not all motherboards do.

[greshoff]

I shorted the switch terminals on the motherboard and it powered up which indicates the its the case switch. Is this assumption correct?

[peterb]

Yes!

(0r the wiring to it)

Had you done anything to it before the fault showed itself? You might have dislodged the connection.

Some switches are mounted on a sub panel and the switch button operates it from the front panel. If that has become dislodged, the button might not be operating the switch.

[Zak33]

slim possibility as follows:

sometimes when a PC is powered off wrongly (power cut/lose plug in the psu that wobbles/someone unplugs you to vacuum around your PC-bound body) the PC simply won't boot.

This has, if we're all honest, occured to everyone at some point.

Then.. after hours of swearing you give up and .. tomorrow it just works.

Sometimes the BIOS gets properly baffled. This is not a technical excuse.. hardcore hardware people reading this are screaming at me now.... but that because it's happened to them too.. and they STILL dont know why


when you shorted the power on pins, you might POSSIBLY have got lucky.

So: test the case switch... use a torch...and some old wire... wire the torch bulb through the case switch using the torch battery so it's safe.. see if the switch is ok.

I bet it's OK... and while it wont help you at least you know!

[Lee H]

Does the case have a reset switch at all?

If it does, why not swap over the Power/Reset headers on the pin area and use the reset switch as the power button if its still problematic.

I did similar for well over 6 years on my older PC's case with no issues at all

[greshoff]

I replaced the power switch with the reset switch but still doesn't power up. Now when I short the the switch terminals on motherboard nothing happens. The power clip test still starts the PSU. Is there a way to test motherboard? Despite the the PSU starting up with the paper clip test, could this still be the issue? I don't have a spare PSU to test with

[peterb]

Unlikely to be the PSU if it is starting correctly by directly connecting the start pins together. It is now looking more like a motherboard issue. Is the case switch connected to the correct pins on the mono? Is it actually plugged in? It is very easy to 'miss' the connection, so double check.

Had you done anything to the machine immediately before the problem showed up?

[greshoff]

Yes case switch is correctly connected to motherboard. As I said when I short the the switch terminals on motherboard nothing happens. I opened the case to check if it needed a clean out in terms of dust. No hardware or connections were disturbed. How can I test the if the motherboards is OK or not? Thanks

[greshoff]

I have just tried the power switch and the computer turned on, once. I then switched it off connected all the usb connections and tried again and nothing. Unplugged all usb connections opened it up again and tried power switch again but nothing. Very strange - Any pointers
One further point. The computer at times couldn't be woken up from sleep and a hard reset was required. Not sure if this is connected to my current power problem. Possible more a Windows issue

[greshoff]

Update-The computer now boots OK. I didn't do anything apart from trying the power switch. I would still like to work out what the issue could be