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John73
10th February 2013, 07:05 AM
Just got my laptop fixed - I won't go into the story but bloody hell.

So now I have to fix my desktop - I've only had a very quick look and my initial diagnosis is dead mobo.

I turn it on, LED on the mobo lights up, fan on CPU heatsink comes on, fan on video card spins up. DVD drive opens/shuts fine. So there is nothing wrong with the power supply. But nothing on the screen.

So far I've only got as far as taking out the video card and powering up - with and without the video card plugged in I get no beeps at all. The PC speaker is connected and I'm positive that it used to work - so not getting any POST beep codes would be a sign of a dead mobo? Possibly the PC speaker is stuffed, but that would be a first for me - they are pretty simple those little speakers and I've never ever had one of those stop working.

I left the computer going for maybe a week before I tried to use it and couldn't get the monitor to show anything. Plasma TV is not working properly either as of a week or so ago - do I just try ringing my insurance and claiming some sort of power surge for both? :unsure I'm not 100% sure this is the case, but it seems odd that too fairly sensitive electronic devices started playing up at different times.

Homepin
10th February 2013, 07:09 AM
RAM would be where I would start

XeviouS
10th February 2013, 07:16 AM
First place I always start is to re-seat everything. Ram, power connectors etc.

Mikie
10th February 2013, 07:18 AM
Has pc got on board video? - if not will not start if you pull the video card out

Most common failure on pc is power supply . Test with known good one.

John73
10th February 2013, 07:21 AM
I will check all of those things - but it seems weird that I'm getting absolutely no beep codes from the internal speaker. I've had plenty of RAM issues over the years, and also video card issues and I've always got a beep code from the speaker.

I'll pull the PC apart today, blow out the dust and put it all back together and see what happens.

EDIT: And no, the PC doesn't have on board video

Fish Tales
10th February 2013, 07:37 AM
any storms a week or so ago?

DKong
10th February 2013, 07:46 AM
Had exactly the same thing happen to both my MAME cabs and it was the video card in both, try another video card if you can.

John73
10th February 2013, 07:53 AM
any storms a week or so ago?

We had a stack of rain a few weeks ago - I'm not 100% when the PC stopped working as I'd left it on and hadn't touched it - didn't even realize that I'd left it on. There were a few storms around, nothing major but it doesn't take very much of a surge to blow a critical part of a PC.

Will do what everyone has suggested and hopefully get to the bottom of the problem.

The Pinny Parlour
10th February 2013, 10:46 AM
Make sure you have the speaker on the corrent mainboard header. I've seen plenty of speakers connected with power on ground (back to front).

Reseat all connected components (especially memory and graphics card).

Remove mainboard battery and remove the power from the PSU. Press the power button on the front of your PC several times. Nothing will happen of cause.

Put power back into the PSU and retest.

FLEX
10th February 2013, 11:12 AM
My guess is one of three things;
Power supply,
Motherboard,
CPU,
Ram,

lol, could be any of these.
I guess a good way to start is to tell us what the system details are and the age of it.
In the end though, if it is either one of these components and the system is over a couple of years old, then your going to have a hell of a problem replacing individual parts due to all the changes in hardware over this time. Sure the parts are easily sourced but what part do you get first? Better off buying a brand new bare bones system for a couple of hundred bucks these days with possibly better specs then bother trying to fix the one you have. Once again though, this only applies if the machine is over 12 months or so old.

casperthefriendly
10th February 2013, 11:32 AM
Try removing EVERYTHING from the motherboard and see if it will POST - take all the ram out, video card, HDD, keyboard, mouse etc and see what happens.

If the mb isn't cactus, with a bare board you should still get something - POST beeps or BIOS screen. If it tries to boot with everything removed, then add in some RAM and a keyboard and take it from there...

John73
10th February 2013, 07:26 PM
Took out the two cards (video & wireless network) and the RAM. Got some compressed air and blew all the dust out of the heatsinks, card slots & ram slots, put it all back together.

Just powered it up and I heard two beeps. More beeps when I take the video card out which is a good sign. Don't currently have a monitor to try it on, but will do tomorrow night but all signs point to it working again :)

So it may have just been a case of dust in either of the card slots or RAM slots, but in my experience it still should be giving an audible POST code.

Oh well, will get a monitor hooked up tomorrow and let you know - though if it does start working I'll never know exactly what the fault was :lol

Bloody computers

Guy with a Pinball
11th February 2013, 01:06 PM
As previously suggested, the way to troubleshoot these type of issues is to go back to basics. If possible, use spare components that have been TESTED and proven to work (i.e: tested & working PS, Video Card, Memory & CPU). Take nothing for granted - assume one or more of your existing components are faulty. A common fault with power supplies is whilst the 12V rail is good, the 5v rail can be faulty - also the RGS (ready good signal) for the PS can be faulting therefore giving the impression that the PS is working properly when in fact it is not. Just about guaranteed that if you use spare TESTED and proven components in your troubleshooting, then you will quickly identify the fault saving yourself hours of pulling hair out and kicking the cat. Of course this only works if you have spare working components. An alternative method is to test your suspect components on another working system - caution here however as if you have a seriously faulty/faulting component, there is always a risk that it will damage other components if introduced into a working system - check for obvious things such as blown caps or burnt tracks etc.

I've found, in order of faultiness, the following components will be the likely cause:

Power supply
RAM
Video Card
HDD
Optical Drives
CPU
Motherboard

:)

casperthefriendly
11th February 2013, 06:26 PM
Two beeps on POST is still an error though, whether you've got a monitor plugged in or not, but you need to have it connected as the error appears on screen.

Did you have a keyboard plugged in when you tried? It's odd that you got more beeps when you pulled the video card out, but that might have been the BIOS detecting that the hardware had changed. You really need it hooked up to a monitor to see - use the video port on the motherboard itself and leave the video card off.

You should only get one POST beep if all is well.


Took out the two cards (video & wireless network) and the RAM. Got some compressed air and blew all the dust out of the heatsinks, card slots & ram slots, put it all back together.

Just powered it up and I heard two beeps. More beeps when I take the video card out which is a good sign. Don't currently have a monitor to try it on, but will do tomorrow night but all signs point to it working again :)

So it may have just been a case of dust in either of the card slots or RAM slots, but in my experience it still should be giving an audible POST code.

Oh well, will get a monitor hooked up tomorrow and let you know - though if it does start working I'll never know exactly what the fault was :lol

Bloody computers

John73
11th February 2013, 07:29 PM
Two beeps on POST is still an error though, whether you've got a monitor plugged in or not, but you need to have it connected as the error appears on screen.

Did you have a keyboard plugged in when you tried? It's odd that you got more beeps when you pulled the video card out, but that might have been the BIOS detecting that the hardware had changed. You really need it hooked up to a monitor to see - use the video port on the motherboard itself and leave the video card off.

You should only get one POST beep if all is well.

I had nothing at all plugged in - no monitor, keyboard, mouse etc. It was one beep, followed by a second one several seconds later. Didn't get around to plugging the hard drives back in either, so it's possible the second beep is indicating that there is no bootable device present. Haven't got around to looking at it further, but I will do this week - I'm pretty sure it will be all systems go when I get everything hooked back up - it's definitely better than getting nothing at all out of the system a day ago.

WOKA
11th February 2013, 09:32 PM
Clean your memory with a eraser and re-seat your video card.

John73
14th February 2013, 07:49 PM
Clean your memory with a eraser and re-seat your video card.

A guy showed me the eraser trick about 15 years ago - the best tool a computer tech can keep in his toolkit.

Still haven't got around to plugging the PC in to see if it's all working - maybe this weekend.... absolutely buggered from work and got more house cleaning up to do before I muck around with this stupid PC :(

The Pinny Parlour
14th February 2013, 09:18 PM
A guy showed me the eraser trick about 15 years ago - the best tool a computer tech can keep in his toolkit.

Still haven't got around to plugging the PC in to see if it's all working - maybe this weekend.... absolutely buggered from work and got more house cleaning up to do before I muck around with this stupid PC :(

I'd say a screwdriver actually.