Quite dead PC....

[Blues&twos]

Hello All.

I have a three year old Mesh desktop PC. Today the PC booted normally but then ground to a halt at the login screen. Restarted using the on/off switch on the front of the PC (as no response to anything else)....then....

The PC hardware powers up (fans etc), internal lights come on, the hard disk light comes on for about 20 sec then goes out and stays out, the hard disk spins up but there's no POST screen, no BIOS beeps and no video output, so it doesn't seem to be getting even as far as POST.

I've tested the power supply and get a stable 5.16v and 12.12v, so unless I've missed one, it looks ok.

The cooling fan heat sink over the CPU was chocker with fluff...I've got a feeling the CPU might be cooked or the ASUS motherboard has turned up its toes.

Anyone got any other suggestions before I.....and I can barely type the words......pay someone to fix it?

Thanks all!!

[green granite]

You could try removing all the cards, all but one stick of ram, disconnect the HD then try and see if you get any beeps then, if not try it with a different memory card plugged in. If it beebs then replace bits until it goes faulty again. But I don't hold out much hope.

[Blues&twos]

Me neither. I can't get it to do anything.

I'll take it into work tomorrow and call in some IT department favours....if nothing else hopefully I'll be able to diagnose a seriously knackered major component and confirm the HD is still functional.

[Albert Square]

When you check your power supply, also check pin 8 on the ATX connector. This gives 5v when the PSU decides it is nice and stable. This tells the MB that the power is OK and the processor can start. It happened to me and a new PSU fixed it.

[P.Pilcher]

If your CPU fan was full of fluff, it stands a chance that the same was blocking your PSU fan which has caused it to die as well. A new PSU is therefore a red hot favourite to bring your machine back to life.

P.P.

[Keef]

Does it do absolutely nothing on power-up? Does the on button on the front make anything happen?

I agree the first probable diagnosis is dead power supply. The second is "bad contact somewhere". The third is "dead bit" - anything from a minor part to the motherboard or CPU.

[Blues&twos]

Hello again. PSU is fine (voltages all stable, no obstruction to vents, fan working OK), the machine does switch on when the power button is operated, the HD spins up, the lights come on, the CD drives start up, the fans all start running.

The Power On Self Test (POST) doesn't run, and nothing else happens, screen stays blank.

Checked all connections were secure. Have removed, inspected and reseated:

Memory cards
Graphics card
Sound card
Processor

Got my IT dept to check it out today, they found the same as me. They were able to connect the HD to another spare PC from which I was able to retrieve some data...but not all as the hard drive isn't very healthy either (bad sectors, some files not readable etc). Not looking good for the motherboard/processor.

So, repair or get a new better spec PC for half the price I paid for my original one?!

Thanks for the replies.

[green granite]

Assuming your monitor, keyboard etc are ok then have a look at the power sellers on E-Bay, I got a tower for about £100 less than I could source the same spec anywhere else, so far after 12 months it's not even hiccuped, apart from the fan on the graphics card getting a bit noisy occasionally.

[Keef]

That sounds like a dead mobo. You can get them quite cheaply (maybe even the same model). Whether you'd want to bother, or just get a complete new tower, is another matter.

Connecting the old HD to the new machine (as a slave drive) should allow you to get to any key stuff you haven't backed up.

[Blues&twos]

Cheers everyone - discussed with Mrs. B&t, looks like new tower unit will be ordered.

Ho hum!

[Albert Square]

Did you check for 5v on pin 8?

[Blues&twos]

Bugger. Knew I'd forgotten something. The PC is at work in bits at the moment....

Double bugger....Mrs. B&t has already ordered a new PC.

However, just to torture myself I will test pin 8 on the ATX connector on Tuesday when I go back to work and let you all know whether I've been a complete muppet or not.

:ugh:

[Albert Square]

Probably time for a new PC anyway so don't worry about it. Hope you keep all your data OK.

[Blues&twos]

Hello again.

As promised, although a few weeks later than originally stated I have finally got round to fully testing my dead PC's power supply.

All functioning - with a nice stable 5.16v on pin 8 of the ATX connector.

So I have stable 12.12v, 5.16v and 3.41v on the relevant ATX pins.

The motherboard LED comes on and stays on, but I get nothing from the PC.

Definitely looks like mobo failure now! Good job the new PC is being delivered in a week.

Thanks for everyone's suggestions, I'm managing to get most of my data back too off the old hard drive. Once I've got as much as I can off and secure I'll try getting Windows to "repair" the disk (it's plugged into another machine)...although I know this can also lead to loss of data. Nothing to lose at that stage though! :ok:

[bit-twiddler]

Sounds like a MB or Processor problem for sure - probably overheating related as you surmised.

For future use it's well worth getting one of these fault finding cards at about 1.50 delivered.

DealExtreme: $2.57 PC Motherboard Repair/Troubleshoot Boot-Failure Diagnostic PCI Card (http://www.dealextreme.com/details.dx/sku.21997)

Basically put in PC, switch on, read code and it should give you an indication of the faulty hardware.

[Blues&twos]

Thanks for that bit-twiddler! I presume you have one of these little boards. From the reviews I've read on the internet they seem to be easy to use and very popular, with maybe a question mark over the English version of the instruction book...but apparently not too bad.

Consequently I've ordered one. How can you go wrong at $2.57??

I'm willing to guess that my boss will be borrowing it at some point...always building, rebuilding,moaning, rebuilding his Pcs.

I'll report back if the card gives me a diagnosis worth mentioning!

[Navajo8686]

From experience of having repaired a friend's PC it may be worth investing in a new battery for the motherboard. Cost about £8 (ISTR) but the PC sprang into life after and is still working fine. It's very low voltage but it kick starts the boot process and if it is dead then it won't boot.

Oddly that is a Mesh PC as well - not sure of age to say that this is a common failure though.

Hope it helps

:)

[bit-twiddler]

Thats a very good point - if the cmos battery is dead then you'll get the same effect as if the reset jumper has been moved i.e. it just doesn't boot.

Usual MB one is a 2032 and should be a few quid and a 2 minutes job to change. If the voltage on it is much below 3.3 then worth changing.

The card on the dealextreme link I posted is very well made for the price and it's worth downloading the manual from the link on the discussion thread at the bottom of the item to se what it show.

Warning - don't go scanning around the DX site as you end up buying loads of odd things :) (e.g. disc drive adaptors, phone sim unlockers, LED torches that look like pigs etc.) It's where a lot of Ebay sellers dropship from.

[Blues&twos]

I confess to spending a considerable time after placing my order looking at all their other stuff and thinking "That's a fantastic gizmo...maybe I should get one of those. Oooh. And that. And maybe that too...."

Will change the battery and see what happens, but I'd be surprised if it makes any difference. Would the CMOS battery dying cause the PC to hang after it had booted? I know it can mess up settings and times dates etc..

[Navajo8686]

I found that the PC with a flat CMOS battert would start to boot, get so far and then just curl up into a ball and die.

Took a while to work it out! :}

[Blues&twos]

Well, I got my motherboard testing card (thanks for the tip, bit-twiddler)and tried it out on my dead PC yesterday.

It is currently suggesting that the CPU is not running (PSU checks are all OK), although the CPU does start to warm up to the touch. A friend of mine has some spare, compatible old CPUs and a couple of machines I can fit my suspect CPU into so some more component swapping/testing will be done hopefullly on Monday.

[green granite]

Could well be a dead cpu or it could be that the clock is not running. The former is simple to repair, just change it. The clock is not so simple.