I have just built my first computer but it keeps on restarting itself with no warning whatsoever. This usually happens when I'm playing a game or during DVD playback, although it has been known to happen before the comp even reaches the user login page. However, I have run stress tests for the CPU (Prime 95) with no problems. The cpu was peaking at over 72C so I have underclocked it until I get a better cooler, and now it peaks at 62C although it still keeps on restarting.

I have the following configuration:

Athlon 2400 XP (underclocked to an 1800XP)
512M PC2700 RAM
Aopen CD-R 48x16x50 drive
Samsung DVD 16x drive
Chaintech APOGEE deluxe mb
Chaintech GF4 Ti4200 128M (AGP 4x) vga card
Maxtor DiamondMax Plus 9 60G Hard drive

Can someone please help, because it's getting effing annoying. I feel it could either be down to improper cooling, a faulty hard drive or a lame psu. If it matters it is a TUV Tsunami Switching Power Supply rated at 350W. It has the following specs:

+3.3V 28A
+5V 30A
+12V 15A
+5VSB 2A
-5V 0.3A
-12V 0.8A

Is this enough for my comp? I would really, really apreciate any kind of help because it's driving me mad. Another thing is that the comp itself is in a badly-designed desk; it is surrounded by thick slabs of wood on three sides with virtually no where for the hot air to go except back into the comp.

Thanks

PSU could be an issue..If you have a spare wouldn't hurt to try a different one.
Seems this happens while playing games i would think that this may be a "LOOPBACK ERROR" which M$ has not fixed with XP so i'm thinking that it also might be related with "ACTIVE X "

With that aside do you have Via chips and are you using NIVIDIA? This might just be a driver issue??
I'm fishing here so bare with us a lot of things can cause reboots...
are you using power management?

And welcome to PC Guide

First thing I'd do is change the behaviour for "automatic reboot"... For Windows 2000 the procedure is this (I hope XPis something similar):

- Right-click "My Computer", select "Properties";
- Select "Advanced" tab, the "Startup and Recovery..." button;
- Remove the checkmark by "Automatically reboot".
- OK, OK to close everything, then restart the machine.

At least then you might get to see some error messages that could help.

Thanks. I've tried both suggestions, that is I've updated the via chipset drivers and turned off auto reboot. The problem still occurs, but this time I have the following screen to greet me. What do I do now? Bios shadowing and caching is and always has been turned off, I will shortly try to flash a new bios ('aint got a clue how to do this, but I'm sure it can't be too hard):D

I bet that it's your BIOS ver. Check to see what BIOS ver. your system is using before you flash. Your MOBO may have been manufactured before the Athlon 2400XP hit the market.
One more thought. Maybe your MOBO does not like your RAM.

Tracking down intermittant problems takes patience.
You've got too many peripheals and software issues to do any good investigating.

A better starting point would be to set the BIOS to it's defaults, unplug evrything but the hardrive and run your OS in safe mode.

Add in other drivers, software features and hardware in a logical order.
First the "chipset", then video, sound etc....CDs and DVDs, game devices, can cause problems as well....

If your methodical enough, you'll discover just when the "random reboots" start. Trying a diagnostic OS - like '98 is not out of the question.

Look in your BIOS, see if there is a CPU temperature monitor routine, and if there is, is there a high limit, and can you raise it a couple degrees.

I've tried changing the temp. limit, it makes no difference. I would like to think that its a driver problem, because most of the drivers I have installed are not certified by microsoft. I tried unplugging stuff; found that the wires were stuck in so well it was maiming my fingers trying to get them out. I did launch safe mode though, and depite my efforts to mess it up the comp behaved perfectly this way- admittedly, I was unable to launch programs which usually caused the reboot, such as IE, UT2003 or play a DVD. Assuming it doesn't crash in safe mode, what does it mean it must be a driver problem?

Not necessarily. If it is a heat problem, it would be most likely to occur when you are running programs that are working the system the hardest and you can't access those readily in Safe Mode. You might want to try running a program that pushes the CPU in Safe Mode and see if it happens. This would suggest that it is heat. Regardless, I would try to fix the heat problem ASAP. This may mean moving the computer, installing more fans and installing a better heatsink/fan on the CPU.

Oooh - Deja Vue!! Saw this sceen today on a friend's computer I was sorting out.
He had a mixed up system - an upgrade from ME to XP had been performed, but the system was sulking.
Had to reinstall XP- the screen came up saying that an internal power supply fault had been detected - BS! XP was just not doing it's job properly. Run a diagnostic such as norton over it to see if it can sort out any problems - the chances are the problem lies with XP's power management system falling on it's backside.

Decided that the best thing I could do would be to re-install xp, so I did. This time I wiped the disk clean to do a full install instead of an upgrade from 98SE. However, just after the disk had been formatted to NTFS, and windows had started to install, the infamous blue screen popped up again. Not only does mean that it MUST be a hardware problem (I assume) but also that the problem is getting worse- installed both 98, then xp without any problems at all; with 98 there were very few problems.

I'm going to buy a new cooler and some case fans, although I doubt very much that it's the heat, because I know that at times the system has rebooted when the cpu temp is below 55C; at other times it goes above 70C before giving up. And it's also unlikely that it's the power; I reinstalled windows with only the bare minimum on the board (cpu, ram, vga and dvd drive) and a 350W psu should have no problem with just this.

Can someone please tell me if there is a possibility that the cpu was permenantly damaged when its temp went up to 72C (this didnt happen often, as soon as i noticed i slowed the fsb speed). If not, what could possibly be the problem? I should mention that before trying to install xp I ran a diagnostic test on the hd (powermax.exe) which included a factory re-certification test, and it passed; so it probably isnt the hard drive at fault.

I'm going on holiday for 10days so i wont be able to reply for a while, but please check back in a couple of weeks by which time i will have done. I need all the help I can get- I'm almost regretting the fact that I decided to build my own comp in the first place!

It's possable the cpu is going why don't you take it off and inspect what the paste or the pad looks like paste could have some voids in it.
clean it, use new paste and reseat..

Well I'm back. I've tried repeatedly to re-install XP from a clean hard drive, and each time I've seen the blue screen before it's finished. So I gave up and put Win98 back on, and it installed easily first time; and since then I havn't seen a single blue screen. Um, does this mean once again that it could after all only be a software problem? Is it possible that enough of win xp was installed for it to successfully disagree with the computer in some way? Or maybe it just doesnt like fresh installs (last time it was an upgrade).

That said, win98 is being abnormally unstable. Both word and excel 2000 performed illegal operations within thier first hour of use, smth that virtually never happenned on my old win98 computer. Age of Mythology repeatedly crashes, with it having performed a critical error midway thourgh the game. And generally the comp keeps on locking up, although I have not seen a blue screen yet.

I would like to put xp on, should I wait till some new case fans have arrived and the temp has therefore dropped? Or is it unlikely to be a temp issue? More to the point, what's going on, and what can possibly be done about it?

On another note, I am considering buying the flower cpu cooler from quietpc.com, cos my comp sounds like an elephant farting. Can someone tell me whether this would be wise considering the fact that at the moment at least, better cooling is more important then quiet cooling? In the specs airflow is not mentioned, so I have no idea whether it would be as good as my current Akasa 785 CU cooler.

And yes I've reseated the cpu, the temp has only dropped a couple of degrees.

Once again thanks everyone for your help!

There are three things that I would consider....

1. That warning about the power supply is indeed true. Whyzman posted a very interesting article on selecting power supplies, last night. It details something that I have believed to be true but didn't quite know how to express.

You are cutting it very close with only 15A on the 12v leg.

http://members.shaw.ca/need4speed/Power%20Supply%20Choices.htm

2. That your heatsink is cupped and is not making very good contat with the CPU. To test this, take it off again flip it over and stick a strait edge diagonally across it, then look at it. If you see light between the straight edge and the heatsink it is cupped and either needs to be replaced or lapped.

3. That your desk is acting as an oven and slowly cooking your computer. If you are handy with a drill, add some ventilation holes, near the exhaust areas of your computer, also a couple near the intakes wouldn't be a bad idea, either.

Even though Athlon CPU's are rated for a max of 90 deg. C, they can be damaged if they get to 70 deg. C and over, which was the case with yours.
So it's possible that your CPU is damaged, and the only way to find out is to swap it out.

Also, according to specs that I read, your heatsink and fan are designed to work with Athlon CPU's up to the XP 2100, assuming you're using the stock fan rated at approx. 25 cfm. So you definitely want to replace that cooler with a higher capacity unit.

However, while using this cooler may cause your CPU to run a little hot under a full load, it bothers me its temperature initially rose all the way to 72 deg. C, or even to 62 deg. C after it was underclocked, unless the heatsink and/or fan is defective, thermal compound(or the proper amount) was not applied between the CPU and heatsink, the mounting of the heatsink on the CPU die is incorrect, or the hold down clips are improperly designed, applied, or are broken.

Hmmmm. Well according to the akasa website:

http://www.akasa.com.tw/akasa/coolers/ak785cu/ak_785cu.html

the 785CU cooler can take up to the Athlon 2800+, which seems laughable to me. I realise that I will definitely need to replace the cooler- I was thinking of getting a quieter one anyway, so I 'spose I could kill two birds with one stone, such is the rather crappy cliche. However, I assume that the quieter a fan is, the less powerful it must be..oh well. Nehoos, I've heard nothing but good things about the Thermalright slk-800, so I'll probably be getting me one of those, or at least the slk-700. The tricky thing is to find a fan with significant airflow which is below 35dB (the current level). Any pointers?

If the cpu is damaged, I'm really hoping that I can get some money back, cos the cpu, mb (which supplied the possibly defective paste) and the cooler were all supplied as part of a package deal. And I doubt it was my technique, I followed turorials closely.

If I am going to do this at all, I might as well do it properly: is it worth paying the extra for AS3?

You're correct about the Akasa cooler.
I was looking at the specs for the 785, not the 785 CU.
Sorry about that.

It's entirely possible that your MB/CPU/heatsink package was fabricated without any(or with too much) thermal compound applied, with the incorrect heatsink(or one that's improperly mounted), or with the wrong type/size/speed fan installed.
But the bottom line is if everything that was installed on the package was in accordance with the supplier's specs and was installed properly, and the heatsink fan was running when the system was initially powered up, then there's no reason for the CPU to get to 72 deg. C other than faulty workmanship on the part of the supplier IMHO.
And it appears that you may have a good case for a warranty replacement.

Check fans from Sunon and YS-Tech. They seem to run at lower decibels when delivering the same cfm as other fans, like the Delta screamers.
And I do not think that you need an 80 cfm fan for the slk-800, like the Thermalright site recommends. Something around 50 cfm should work nicely.

I strongly recommend AS3. It will keep the CPU running a few deg. cooler than just about anything else on the market's, and it's the thermal compound to which all others are compared.

Sorry I've been so long replying, I've just got loads of school work. Anyway: unfortuantely it was me who assembled the package, the deal was just that if you bought them together you got money off, they still arrived individually. However, it still sucks, if there is a hardware problem it can only be thier fault, assuming I applied the compound properly.

One thing though, when applying the thermal paste I followed AS3 instructions instead of instructions given by the mb manual- the only difference is that with AS it is applied straight onto the processor rather then the heatsink, wheras it is the other way round according to the manual. I don't know why this should make a difference though.

Since the last post I can confirm that win 98 is being rediculously unstable- an open program will randomly (theres that word again) perform an illegal operation and close down, but the comp doesnt restart. E.g I had winamp open for 45mins, i wasnt touching the comp, when suddenly the music started repeating itself and and it closed down. And half way through browsing iexplore will perform an illegal operation, bastard.

Do these illegal operations point to it being more one thing then another? i.e. assuming it is cuased by the same thing that casued the restarts in xp, is it more likely to be a processor program then a power supply one?

One more thought- how much heat does it take to damage an mb chipset?