Random crashes = bewildered user

[reno84]

Lately my computer has started crashing seemingly at random. It simply locks up, not responding to any inputs and the display stays the same. The crashes sometimes occur after hours of use, sometimes before I even get into windows. A few times its happened while doing the memory test as soon as I power up. This leads me to believe it is a hardware problem, as windows needn't have booted for the problem to occur.

My system is...

A bog standard mobo courtesy of the company "Motherboard".
300w PSU
AMD Athlon 1800xp
GeForce4 4200ti 128mb
1x 256mb PC100 SDRAM
1x 256mb PC133 SDRAM
40Gb 5400rpm Maxtor HDD (set as primary master)
LiteOn CDRW (set as primary slave)
52x CD drive (set as secondary master)
PCI 10/100mbit LAN card
PCI 56k Modem

I know my IDE components are setup kinda wierd - it came setup that way and I never bothered to change it. I fail to see how this could cause a problem though.

I've used the system for around half a year without any problems whatsoever, with all the components installed. Only recently the problem has arisen. Ive formatted the HDD and removed and refitted all the components since the problem occured, and for a while it seemed fine but has recently started freezing randomly again.

The problem seemed to disappear when I uninstalled and removed my modem. Any ideas as to why the modem could be causing the problem? Or do you think this was just coincidence?

I have sometimes gone 3 or 4 reboots without having it crash on me once, but sometimes I've had the crashes occur frequently and been unable to use that computer.

Often when I reboot after the crash, my monitor doesn't pick up a signal and I have to reboot again, or sometimes even more, before the monitor picks up anything. Not sure if this has any relevance, but thought I should mention it.

Any suggestions are very welcome.

 

[brianp34]

The problem seemed to disappear when I uninstalled and removed my modem. Any ideas as to why the modem could be causing the problem? Or do you think this was just coincidence?

A faulty pci modem could be causing your problems. If the problem has gone away when the modem is uninstalled, I'd say that's a pretty good guess. Do you have another you could substitute in for that one?

 

[reno84]

I guess I could take out the one from the computer I'm using just now and test it. I guess I'll give that a shot tomorrow. Thanks for the advice, I'll let you know if it works out.

 

[mechBgon]

I see a few potential issues besides the modem:

• You have an AthlonXP, but one stick of PC100 memory too. The AthlonXP needs at least PC133 memory because of its 133MHz frontside bus frequency, and is probably forcing the PC100 to attempt PC133 speeds. The alternative possibilities are not good either (out-of-sync operation between memory & CPU, or an underclocked AthlonXP running at 100MHz bus to stay sync'ed to the PC100 memory)
• Possibly not enough power... for the parts you've listed, I would only use the better & best 300W units, certainly not an off-brand. Quality first, wattage second. What brand & model does your power supply's label say? It may be failing.
• PCI cards possibly causing an IRQ-sharing situation
• Unknown-pedigree motherboard

Could you possibly find some markings on the motherboard to help identify the manufacturer? That would help me track down its PCI IRQ-sharing arrangement to suggest an optimal setup for your PCI cards. The motherboard's model is usually silk-screened somewhere on its surface.

As an alternative, a decent 350W power supply (Antec, Enermax, Sparkle Power, Enlight), a 512Mb stick of Crucial PC2100 DDR and an Asus A7N266-VM motherboard should lay the gremlins to rest for good, if you want to make a fresh start.

 

[reno84]

My motherboard is actually made by a company called "motherboard". The fact that they use the slogan "The brand you can trust" certainly doesn't fill me with optimism when it comes to its quality! It is a model "V266B", although I can't see that info being of too much use. It is capable of running PC100/133 SDRAM or PC1600/2100 DDR. I have tried running the system with only the faster AND only the slower RAM in, and both still had crashes.

The PSU is made by a company called "ADT", and has a sticker saying "Pentium 4" on it so I assume its MEANT for that. It came with the system when I bought it, with the spec above (minus the extra PC100 ram, which I am borrowing from a friend). Could the problem be having too many devices running from a low quality, low wattage PSU? That could explain why removing the modem and lan card saw the problem disappear. I went to a lan party with the lan card in and modem out, and I didn't have any crashing problems then.

For the time being, a new base setup is a little outta my wallet's reach. As a poor student I can scarcely afford good food let alone a new setup under a year after I bought this one It is my birthday in a few days however, and if some family member doesn't get me the 512mb stick of PC2100 DDR ram I asked for, then I'll certainly be buying some a few days later.

Thanks a lot for that list of suggestions - even if they aren't directly related to the problem its still a lot of useful info about my computer. I had no idea running slower RAM would cause an issue, thanks for pointing that out!

 

[brianp34]

Could the problem be having too many devices running from a low quality, low wattage PSU?

Yeah, that could be it. I don't know how much wattage a pci modem draws from a psu, but I don't think it would be enough to throw the system completely out of whack, especially considering you were using your machine at a lan party and presumably had it under load playing games and didn't see any problems. I wouldn't rule out a faulty pci card...I had a modem in a gateway pc a couple of years ago that caused all sorts of weird stability issues, took out the modem and they all went away.

 

[mechBgon]

Cheetahs can fetch! I found your board, it's a Jetway. Put your NIC in PCI slot 3 and your modem in PCI slot 2 (the slot closest to the AGP slot is PCI slot 1). If the problems persist, consider replacing the modem and/or power supply (get a high-quality PSU, if you do).

 

[reno84]

I removed both PCI devices and had only the PC133 RAM in the computer...and its still causing crashes the same as before. I ran the computer for hours last night and it didn't crash once (multiple restarts too) with the setup i just mentioned, but today I turned it on thinking it would work fine, and it has crashed twice out of two starts. I've now switched to using only the slower PC100 RAM, and its working fine so far but I don't think that will last.

This seems to be some sort of degradation problem - I've had a working computer for months and months, and now, without the addition of any new hardware, it has started crashing. I don't believe I've changed any settings or anything that could cause the problem, so it would seem that some part of the computer needs to be replaced.

Judging by your recommendations, its the PSU that is likely to be the problem, although getting new RAM couldn't hurt. Since my computer is under a year old, by law it is still under warranty. I guess I could pester the place I bought it from but last time I had a problem they made ME pay for transport, which is probably more hassle than its worth. Can anyone suggest a good make and model of PSU to look around for?

 

[reno84]

Oh and I'm not sure if this will be of any help whatsoever, but often when it locks up and I hit reset, the monitor doesn't pick up a signal when the computer loads up. Sometimes I need to reset a few times before the monitor gets a signal.

 

[SuperPickle]

I had that 'no-signal' issue on restarts once on one of my machines. The problem went away with a new (still generic) PSU. I didn't have any stability problems though so I don't know if this mirrors your problem.

I assume you've checked into this, but have you considered the possibility of your PC overheating? How about the cleanliness of your heatsink? Dust can really decrease HS performance.

 

[reno84]

I've removed my CPU/fan/heatsink and checked everything is present and not burnt out. There doesn't appear to be any problems down there, so I'm assuming the problem is the PSU. Since the system crashes more often with more components/ram in, and also more often when i use the faster ram than when i use the slower stuff, it certainly seems to be pointing in the direction of not having enough power to keep the system stable. The non-signal detecting monitor also seems to back up that suggestion.

I've found a 450w generic PSU from novatech for a mere £22, while even a 300w PSU from one of the companies you mentioned sets you back about £45+. Does it REALLY make a difference? I want a working PC for sure, but I also want to be able to afford some new RAM and a new optical mouse. I would definately want to get at least a 400w PSU from now on, as while you have stated that quality is more important than wattage, I can't help but feel its not worth risking an unstable system again.

Do you think a higher power PSU would help at all, even from a generic brand? Or is the wattage really just a sales pitch? If its not worth buying unless I get a good brand, I guess I'll have to do it, but I'd really like to get my hands on as much DDR ram as possible, as RAM is very important for what I use my computer for, and a new mouse would certainly help my gaming and frustration levels (damn those sticky mouse balls!).

Anyway, unless you guys seriously suggest otherwise, I think I'll invest in 512mb PC2100 DDR ram, the generic 450w PSU, and an MS optical intellimouse.

 

[mechBgon]

You took the heatsink off the CPU? Did you reapply some good-quality themal paste? Be aware that the squares of gummy phase-change thermal-interface material that come stock on some heatsinks (AMD retail ones included), are good for only one use. That's right, you take the heatsink off, it's done.

 

[reno84]

Ouch, I'm glad you told me that, I figured it made no difference removing it as the touching surfaces were still the same! Oh well thanks for the info, I'll be sure to get some thermal paste before I use the computer again.

Strangely, I've used the computer quite a bit since removing and checking the heatsink and fan, as well as the PSU, and I haven't had one crash. Nor has it shown any signs of overheating. Still, I'll be sure to get more thermal paste before I do anything more with it.

Thanks for thea heads up there