Sudden no start - random shut downs

[djshinkle]

Hello

Today I experience the oddest thing I have ever seen on my PC.

This morning the power on button would not start my PC. I checked the cable and the wall socket and popped the case to look inside. Nothing seemed out of the ordinary.

I turned the case on its side to get better lighting inside and the PC started right up. I was surprised at that so I stood it back up and it shut down. I hit the power button and nothing happened so I tilted it on its side and hit the button and voila, power. So I let it boot and after its all done and windows is up I can use everything normally with no issues. I turned the tower back up and it stayed on. Not 2 minutes later it shut off again and immediately restarted. The second time it did this it ran a disk check (Im assuming because of the sudden shut downs) and it turned out fine.

Right now the PC stays on like nothing is wrong when its laying on its side. As soon as I stand it back up it shuts down within a minute and restarts.

Its a Dell XPS 420
Intel Core 2 Quad
Q6600 @ 2.4 ghz
3 gig ram
32 bit OS Windows Vista
I have installed:
Nvidia 9800
+Extra Case fans

This PC has worked flawlessly since I bought it a year and a half ago (and immediately installed the card and fans). This is the first issue I have had and it feels like some sort of power short, rather than an actual PC issue.

Any ideas?

Thanks in advance.

 

[Computerpete]

Sounds like your switch might be faulty what I would try is jiggling the wire to the power switch to see it shuts down.

 

[djshinkle]

Ok, just tried messing with the wires to the power switch. Didnt shut it off when I did it, it stayed running. The button does however work when the PC is on its side (as in, allows me to push it to turn it on and hold it to turn it off).

Im not sure its the button considering that when I stand the PC upright it powers down and restarts about 1 minute after I log into windows.

 

[Arris]

I'd try re-seating the ram and video card.

Could also be something like the heatsink not being in full contact with the CPU when its stood up but usually that still results in a post then a shutdown when the temp hits unsafe levels. Try grabbing CoreTemp or other another free program to monitor the CPU temp both when its on its side and before it shuts off when stood up. Or you might have temperature readings in your bios, if so you can go into the bios when the machine is on its side, then stand it up and see if the temps shoot upwards...

 

[djshinkle]

Well now that I have given it some time I have more news so to speak.

I put the case panel back on. The temp dropped to 99 degrees (F) on core 1. It stayed that way so I opened the internet browser and the temp spiked to 115 degree in core one and two and the PC shut off. Now, it shuts off during boot or RIGHT after I log in. I cant keep trying because it runs a dskchk after so many odd shutdowns and I dont want ti to power off during the dskchk. The last PC I had powered down during a dsk chk and it never ran windows again.

So, now that I have deduced that it is a temperature issue, what can I do? Core one and two are the "trouble makers" since all the other cores seem to be staying in the green.

 

[Arris]

What PSU is in the machine? What wattage is it rated for?
try disconnecting the extra lit case fan? The aging PSU could be starting to struggle with the additional power needed by the extra fans. Don't know why that would be different standing and lying though.. shouldn't be. Unless the fans are being able to get up to speed with less power when oriented differently... Try running with the extra fans unplugged or unplugging optical drive power, just to see if it will run ok standing with less devices...

 

[Arris]

Well now that I have given it some time I have more news so to speak.

I put the case panel back on. The temp dropped to 99 degrees (F) on core 1. It stayed that way so I opened the internet browser and the temp spiked to 115 degree in core one and two and the PC shut off. Now, it shuts off during boot or RIGHT after I log in. I cant keep trying because it runs a dskchk after so many odd shutdowns and I dont want ti to power off during the dskchk. The last PC I had powered down during a dsk chk and it never ran windows again.

So, now that I have deduced that it is a temperature issue, what can I do? Core one and two are the "trouble makers" since all the other cores seem to be staying in the green.

115F is only 46C.
The maximum loaded operating temperature for Core2Quad 6600 can be up to 62C(B3 stepping) or 71C(B0 stepping) - http://ark.intel.com/Product.aspx?id=29765

That's a lower max of 143, upper of almost 160 depending on the stepping your processor is. I think the "Revision" value of CoreTemp should tell you, or download CPUID.

So I'm not sure it's the temperature. If it is then you could buy new thermal paste (most recommend Arctic Silver)as the default compound does become less effective over time and can dry out. With the computer powered off(obviously) remove the CPU heatsink and fan, clean the bottom of the heatsink with a citrus based cleaner, remove the CPU from the motherboard and clean it too. Then follow the instructions that come with the thermal paste and re-insert the CPU and mount the heatsink and fan.

 

[djshinkle]

Ok Im heading out to buy some thermal paste. I popped off the huge *** heat sink and found the side closer to the intact fan to be pretty clogged with dust that I didnt see on my normal cleaning routine. Now I know to look there. Regardless, I need more duster and Im gonna grab some paste to put on my cpu.

I cleaned it all as good as I could with my little brushes and tossed it all back together. It started right up (standing up) and has been on since and all of the temps are about 10 degrees lower. Core one is at 94 degrees right now and holding strong.

Regardless, Im gonna buy some thermal paste because it couldnt hurt.

Thanks for all the replies and the help. Possibly just was dust hiding in a sneaky spot but anyways, you guys dumped some good things my way. Thank you very much!

 

[Arris]

Regardless, Im gonna buy some thermal paste because it couldnt hurt.

If you can get some arctic silver thermal paste(last I bought was "5" but might be newer versions around now) it can help drop the temperature a little more. A fresh application when putting a heatsink back on is really recommended.

 

[djshinkle]

Well I got back. Before tearing it down again and putting on the paste I decided to see how it was doing since the PC was still on and running at the same temps as when i left.

I started a heavy program (World of Warcraft) and it made it as far as the login screen then shut down. It starts back up (on its own immediately) and I log into windows. Temp is fine and stable like before. Its 90-99F across the board on all cores. I check the max temp on Core Temp and it says it reached 111F.

I missed your other post about disconnecting the extra fan. I'm going to try that now and then apply the thermal paste.

Foolish me assumed that I fixed it by cleaning up some dust!