PC won't turn on after microsoft update

[acrobat]

I build an HTPC and I've had it working for a day. Last night I saw a few windows updates (including a graphics driver I think), so I ran that and then left the PC. When I passed it later I noticed it was off and I thought it must have tried to reboot after the updates and I assumed it couldn't restart because I had recently set it to power on by typing a password, and I thought that might have messed it up.

So this morning I tried again and it didn't power up at all. So I used the BIOS jumper to reset the bios, but it's still not powering up.

The LED/LCD display lights up, and there is a light on the motherboard indicating it is getting power, but there is no sign of life from the PC at all. Fans don't even turn for a second, no beeps, nothing. I have checked that everything is plugged in, and everything is securely fastened inside and out. I have no idea what it could be All I can think of is to take it all to pieces and start again, as a last resort. So before I do that I thought I could check in case anyone has any ideas.

Thanks in advance.

[Koolpc]

Have you got a PSU tester? Might be a faulty PSU?

[edp33]

Try unplugging the power cable, hold down the power button on the pc for 10 seconds or so(I know it's unplugged!) then plug the power cable back in and try pressing the power button again.

[acrobat]

Thanks for the suggestions. I'm totally stuck and out of ideas now. Since my last message I've taken all the ram out apart from 1 chip and then tried a different chip from a different pack. Didn't help. I also took the graphics card out (it has on board graphics) and that didn't help either. I've also unplugged everything to do with the LED display, and that didn't help. I got it to the point where it was just the motherboard with big 24pin power lead, CPU with little 4 pin power lead, 1 hard disk, 1 ram chip, and the power/reset switches plugged in to the motherboard, and it still didn't boot. Makes me think it points to it being either a CPU or Motherboard fault.

Have you got a PSU tester? Might be a faulty PSU?

I don't have a PSU tester. Something I thought though, is that the LED display still comes on, and the motherboard has a little light showing that it is getting power, so I think the PSU should be ok.

Try unplugging the power cable, hold down the power button on the pc for 10 seconds or so(I know it's unplugged!) then plug the power cable back in and try pressing the power button again.

Tried that, didn't seem to help Thanks though.

[edp33]

I have a gigabyte 780g and that needs two power cables, 24 pin one and a 4 pin near the ps2 ports(it's a bit like the pci-e power cable). If the 4 pin has fallen out or wasn't reconnected then the system won't start. I don't know if your motherboard is similar, you mentioned a 4 pin for the cpu but I take it you are referring to the fan power cable?

[crazyfool]

sounds to me like its your motherboard... neva heard of windows update killing a motherboard tho :S

[acrobat]

I have a gigabyte 780g and that needs two power cables, 24 pin one and a 4 pin near the ps2 ports(it's a bit like the pci-e power cable). If the 4 pin has fallen out or wasn't reconnected then the system won't start. I don't know if your motherboard is similar, you mentioned a 4 pin for the cpu but I take it you are referring to the fan power cable?

Yeah the 4 pin is to power the CPU. The little CPU fan is also plugged in. I double checked all these and it didn't seem to help unfortunately.

sounds to me like its your motherboard... neva heard of windows update killing a motherboard tho :S

Me either. I have to assume it is just a coincidence. Also, because I wasn't watching it, I don't know if the update finished and then tried to restart the PC (and it didn't restart), or if the PC died before it even finished the update.

It is so strange though to have a PC actually working for an entire day, and then it just stops working. It wasn't even under any heavy load when it stopped either, it was doing a microsoft update with nothing else running. I also checked the temps while it was working, and both motherboard and CPU seemed ok.

I have a day off on Wednesday so I'm hoping I will be able to take it to Scan and get the CPU and Motherboard tested, but that is a last resort. I'm hoping it wouldn't come to that, but I'm out of ideas now.

[peterb]

Last thought - try without the hard drive - my first thought would be PSU (what make is it), followed by mobo or cpu. If you have a PSU from abnother system it might be worth trying that - unfortunately testing the CPU can only realistically be done by substitution for a known good one, which would also test the mobo.

[acrobat]

Didn't seem to work without a hard drive either unfortunately I have two drives so tried with both separately and without any. The PSU is a Corsair VX 450W. Unfortunately I don't have any spare components to test it with. My other PC's are Intel. I'll call Scan tomorrow and see if they can test it for me. If so I can see if they can test the CPU and Motherboard and if they work then that will narrow it down a lot. And if one is faulty, hopefully I can get a replacement.

Also the case (which I got from somewhere else) has an LED display which was lopsided, so I will get that replaced too and that would also tell me if it's perhaps the power switch which is faulty. (Which is possible). I won't be able to do any of this until about Wednesday though. Such a shame to have it up and running for a day and now it's back in pieces.

[Koolpc]

LED on the motherboard does not mean the PSU is ok. The PSU could still be faulty!

[peterb]

LED on the motherboard does not mean the PSU is ok. The PSU could still be faulty!

Very true, although Corsair are pretty good. Again, difficult to test without a proper test rig and a dummy load - those cheap PSU testers that are given away - or sold very cheaply - just dobn't do the job - there is no way they can load up the PSU properly to give a meaningful test result.

[TAKTAK]

to rule out it being the power switch on the case, just tap the two pins on the mobo that it connects to with a screwdriver or other metallic object

[acrobat]

Thanks all. I spoke to Scan today and the man said the same thing - that the PSU could still be the fault. And he also thought that was most likely. It would be a relief to me if that was it because it's easy to replace that. I will take it to Scan on Wednesday and they can test it for me. It's a pity I couldn't test it myself but I don't have a spare PSU.

As for the case power switch test, that sounds interesting. I can't do that now because I took it all to pieces, but I'm going to replace that tomorrow because the LED display was wonky on it anyway, so I'll get a new one of those anyway.

Thanks all It's nice to see light at the end of the tunnel.

[Koolpc]

I have a PSU tester and it has never let me down. Very reliable in testing PSU's.

Why not buy a cheap PSU locally, try it in the PC and if all ok you could then return that and get a nice new PSU!

[GoNz0]

yeh pc world are great at test equipment

[Koolpc]

yeh pc world are great at test equipment

Never ever buy from them!! Don't know how you can step foot in the place!