Topic: PC randomly returns to desktop

[Simon]

 The lack of an initial 'beep' is worrying, as this, I believe, is the memory test, isn't it?

No its the POST beep and the sounds it makes can identify problems with memory, gfx or other hardware, not just memory.

It could be a bios problem if its not getting the beep, have you tried using the clear cmos jumper to reset it ?

No, I didn't, San, because on Sunday, I got the impression that the problem had been resolved.  I won't be going up there (to London) again until Christmas now, so it looks like they will have to get someone else to look at it if the problem persists.  

[Simon]

Just to update, there are still problems with this machine.  It has now been to an engineer, who has apparently individually tried a different modem, hard drive, graphics card, and I think even the motherboard.  As we know, it has already had a new memory module.  He has reinstalled XP, and still they are getting the BSODs, which are different each time.  What else could this be?  I'm wondering if a format and reinstall of XP might be of any use?  As everything is still on the PC as it was, software wise, I have to assume he only did a repair installation.  Any other ideas appreciated. 

 

[Sandra]

Its a long shot Simon but I can only think of 2 other possibilities.

It could be a cracked or otherwise faulty motherboard or the PSU isnt providing full power some or all of the time.

Although it could still be a ram fault.

Did you reset the bios ? as if the memory timings are all to cock that could do weird and wonderful things.

[Simon]

I don't know if the BIOS has been reset, Sandra, as I've not actually been near it myself, and am getting the info third hand, from strictly non-techies.  I know you've mentioned this before, and I will suggest that they get their chap to do this, and see what happens, as nothing else seems to have had much success.  Hopefully I might be able to get the machine down here at some point soon, which might make things a bit easier.

[Simon]

Update:  The BIOS has been reset, and still the BSODs randomly appear.  I'm beginning to think the only solution might be a new motherboard, as that is the only part that hasn't been tested so far.  The trouble is, understandably, they don't want to spend out money on guesses.  This PC has never started up very well, and about 4 out of five times, has always to be rebooted from a cold start, as there is no 'beep', the monitor doesn't fire up, and basically, nothing happens until the reset button is pressed.  This has been 'just one of those things', as once started, the machine ran fine, but I wonder if the mobo or PSU could have been faulty from the start?  The problem is, which one to change first?  I suppose the PSU would be the easiest.  Which one would you go for, Sandra?  At least a new PSU might be reusable.  If they get an equivalent mobo, this will be quite out of date, so couldn't really be used for anything else.

[Sandra]

If youre going to visit them to have a look at it just take yours out of your pc and try it Simon.

Its only a 10 minute job or so to swap it, providing its got the P4 connector if needed and has the 20 or 24 pin mobo one 

[Simon]

Yes, that's not a bad idea, Sandra.  They have now been offered a fully working Dell P4 for £150, so they are considering that option, but I'm not sure if the specs of it are up to what they have.  Never having worked on a Pentium, I assume their existing graphics card will be compatible, providing there's an AGP slot, but what about memory?  Is memory the same for AMD or Pentium, providing it's the same format (DDR)?  It seems a shame to just ditch their existing PC, when we know that all the other components work fine, and it's only about 2½ years old.  It also makes me feel bad that it's packed up so soon, seeing as I built it.

[Sandra]

Is memory the same for AMD or Pentium, providing it's the same format (DDR)?  It seems a shame to just ditch their existing PC, when we know that all the other components work fine, and it's only about 2½ years old.  It also makes me feel bad that it's packed up so soon, seeing as I built it.

All ram for AMD and Intel are the same apart from the failed attempt of Intel when they brought out RAMBUS, which was only used for Intel based mobos as far as I know Simon.

Most shop bought PCs only have a 12 months warranty and they probably got a much higher spec pc for the price that you built it for them than if they had bought one off the shelf.

If you do scrap it then keep the bits from it in case you or someone else can make use of them, thats the way most people end up with a few spares for older pcs 

[Simon]

All ram for AMD and Intel are the same apart from the failed attempt of Intel when they brought out RAMBUS, which was only used for Intel based mobos as far as I know Simon.

Most shop bought PCs only have a 12 months warranty and they probably got a much higher spec pc for the price that you built it for them than if they had bought one off the shelf.

If you do scrap it then keep the bits from it in case you or someone else can make use of them, thats the way most people end up with a few spares for older pcs 

That's true now, Sandra, but 2-3 years ago, off the shelf PCs were not quite as cheap as they are these days.  I built that machine for just over £400, including monitor, and to have bought a similar spec from PC World at the time, would have cost them well over £500.  We did the maths beforehand!

Thanks for the other info.  I'll let you know what they decide to do. 

[Sandra]

You have to pay the price of what it costs at the time Simon.

I have just upgraded the CPU in the pc I built in march this year 

When I priced CPUs that I wanted the best deal was the one I got, an Intel 660 3.6 ghz single core CPU with 2mb of L2 cache.
Everywhere was selling it for around £270, its still that price today, but I got it for £215, I think.

I am wanting to get a HD Satellite pci card and the best ones at the moment appear to need a lot of CPU power.
I read a review on it that said it was fine on the 3.8 ghz version of my CPU but if the pc was doing anything else then the picture was jerky.
All the HD satellite card manufacturers seem to say D830 CPU which is a dual core 3ghz with 1mb L2 cache on each core as the minimum requirement.

I have bought a D945 CPU 3.4 ghz dual core with 2mb L2 cache on each core for £99 inc vat and delivery 

I considered the D830 as an option back in march but as it was £244 I decided to go with the 660, the D945 or something approaching its performance was way over £300 

I only fitted it around midnight last night so I havent actually done anything with it yet to see how it compares with the "old" CPU but I have run a performance test on it from Si Soft Sandra and compared it to one I did last week and it looks like on paper it is 25% faster on some things and 50% faster on others 

I have added another 250 gig sata 2 hard drive at the same time so I now have 3 x 250 gig sata 2 plus a 160 gig IDE drive inside it.
I think I have enough capacity for a bit now as I have an external USB 250 gig drive for backups.

I see that Ebuyer has a few 750 gig drives for sale now, maybe when they come down a bit more in price I may stick 4 of those in as a RAID setup so my data should be as safe as possible barring multiple simultaneous drive failures 

[Simon]

Getting back to this troublesome PC, as it seems all other possibilities have been eliminated, the one thing that hasn't been tested is the motherboard.  The PC just does weird things randomly, from blue screen errors, to getting a blank screen, or the BIOS screen on boot up, saying that settings are incorrect.  Pressing F5 to set defaults does nothing, then the next morning, the machine starts up fine, until the nest episode, which could be minutes, hours or even days away.

I have found an identical motherboard (so as to avoid changing anything else), and could install this easily enough, but what other implications could there be in changing a motherboard?  Would Windows need to be reinstalled, and if so, would a new license be required?

[Sandra]

If its identical then it should be ok Simon.

Youd only need to reinstall and activate XP if you changed to a different make or possibly model of motherboard.

[Simon]

Oh, that's good news Sandra. 

[gmax]

That problem could be related to bad capacitors on the motherboard, have a look for any bulging or leaking capacitors,i have seen a lot of motherboards with that problem.

[Simon]

That problem could be related to bad capacitors on the motherboard, have a look for any bulging or leaking capacitors,i have seen a lot of motherboards with that problem.

Thanks, that strengthens the case for changing the mobo.