[vok74]

I have a Dell Dimension 4600 which is around 5 years old.

With increasing regularity and without warning the PC is powering down (it’s not switched off completely as the hard drive light is flashing). If the PC is turned off at the plug and left for a while it will switch back on but usually powers down again.

The PC is usually left on constantly so I’m wondering if it’s an overheating issue.

The power supply was replaced approximately 18 months ago so I don’t think it’s the power.

I’ve opened up the PC and cleared out a lot of fluff around the fan. I couldn’t see any corrosion on the motherboard. The diagnostic lights on the rear are all green (when the PC is on that is!)

It’s not the end of the world as we’ve used it as an excuse to upgrade but I’d like to donate the PC to the in laws so it would be good to resolve the problem.

Any help appreciated. Sorry if I haven’t given enough specs, I’m not overly techie (and I’m a girl….)

Thanks

[BlunterII]

Hmmmm, hi, vok74, I am experiencing the same problem.

My Dell Dimension 4600 PC powers down completely, either on windows loading, right after that or sometime between 1 to 30 min afterwards. The ABCD motherboard diagnostic lights in the back are all green. No strange sound or smell.

Specs:
Dell Dimension 4600 (nothing is overclocked, no onboard video or audio)
- OS Windows XP Home edition
- CPU Pentium 4 - 3.06 GHz
- Motherboard (Dell proprietary 2Y832, 1 x AGP slot, 4 memory slots, 478 cpu socket)
- RAM 2GB (4x512MB SDRAM 2700sticks)
- VCard (Sapphire Radeon 9600XT, ASUS NVidia Geforce N6600, XFX NVidia Geforce 7600GT) tried all 3 with the same result - powering down for no apparent reason
- PSUs (native dell 250W and Panther 450W) tried both with the same problem persisting - powering down for no apparent reason
- HD Seagate 120GB
- 1 DVD + 1 CD/RW-Rom (when testing unhooked them both with the same result - powering down for no apparent reason)


Note (timeline):
- Dell functioned fine for ~ 5 years
- Upgraded my Video card to 7600GT a couple of months ago (12/2007).
- around a month ago (01/2008) we had a serious blackout in our area (I don't have an uninterruptible PS)
- Started experiencing the power downs I've described above
- Bought new 450W PSU (didn't resolve the problem)
- Removed the new 7600GT and replaced it with 6600 - same result, replaced with 9600XT(this one doesn't require an external power supply) - same result
- System shut downs became more frequent (with time)
- Took the whole thing apart. Examine the motherboard. Didn't find any visibly identifiable damage (no leaking capacitators, etc.). Put it back together - Problem persists!



Questions to the local gurus:
-What could be the problem with my PC in your opinion?

-Could it be that my motherboard kicked the bucket? Is there a way to know for sure? And what are the symptoms of a motherboard mulfuctioning in general?
-Might it be the HD? Could a corrupt Windows cause that?

Where do I proceed from here?...



BlunterII

[vaio]

Generally I would associate completely shutting down (rather than a blue screen) to be a power or overheating problem.

Download a testing utility like prime 95 and run that a while.
Whilst doing so monitor the temps reported.....Speedfan will do that for you.

Perhaps your machines are reaching temps where the "safety shutdown" is kicking in.

I would suggest downloading and installing Speedfan before doing anything else.
As well as temps it will also show voltages the power supplies are giving.

(Assuming rigs can run long enough to install said software).

If you get Speedfan running report back with temperature readings and such.

[vaio]

Speedfan
Prime95

[BlunterII]

Download a testing utility like prime 95 and run that a while

Unfortunately couldn't even load the Windows this time. It powered down on me while loading the OS. So I guess it is not an option for me. (BTW the cpu heat sink was completely cold after both shutdowns)

Any other ideas?

(I know I should consider getting a new computer, actually I already did - Dell Inspiron 530 for everyday low intensity apps

I just want to attempt to resuscitate this Dell. It is a good overall system. Used to run most of the games on med including HL2, SIMs2, Stalker, COD4/ Crysis on low settings etc.)


BlunterII

[vaio]

Are you sure the heatsink is in contact with the cpu?

Remove heatsink, get some thermal paste and re-apply and re-install heatsink......good instructions at Arctic Silver website.

http://www.arcticsilver.com/arctic_s...structions.htm

Edited for brain fart

[BlunterII]

OK, I am trying to narrow down the search.

Another step I've taken:
To eliminate faulty CPU as a reason I put it into a different system (Sony Vaio PCV RX-850). It is very similar to my Dell Dimension 4600 and has a 478 socket.
The Sony powered up normally, in Device Manager 3.06 GHz processor is registered (instead of the native 2.4GHz). I'll try to run some graphic intensive program on it and see how it fares)

Originally Posted by vaio

Are you sure the heatsink is in contact with the cpu?

Yes it is in contact.

Besides why would it shut down almost immeadiately after I started Dell? (It was sitting in a cold closet all night. Several seconds doesn't seem to be enough time for it to overheat)


Anything else?


What are the symptoms of the CPU fan not working properly?
Is it possible to test it on a different system?
How do I test the motherboard? By elimination?
CPU -check! PSU - check! GPU - check! DVD, CD-Rom - check! What's next...? Hmmm...

Memory, perhaps? Would a faulty memory stick produce the same symptoms?



(I really appreciate your input! Thank you!)

BlunterII

[vaio]

Memory errors I would expect a blue screen or reboot not a hard shutoff.
Yes,a few seconds would be enough for the protection to cut in and shut machine down.

Re the fan....just turn the machine on with the case side off to check it is running and running correctly.

[BlunterII]

Originally Posted by vaio

just turn the machine on with the case side off to check it is running and running correctly.

Thank you for your reply, vaio.

OK
Took the right side off.
Reseated the heat sink again (just in case, for the 5th time). Made sure in was all the way in, locked the heat sink brackets into place.
Plugged the pc. Turned it on.
The cpu fan is running. The psu fan is running. after 5-10 sec it just shut down.

Any other suggestions?




BlunterII

[Abarbarian]

Take your memory out and try just one stick of memory from your friends working pc . If it works you found the problem .