Random Rebooting

I have a comp that's been playing up now for over 2 months and there is nothing predictable to what its going to do, when I boot it post every time with no problem, but then it may reboot before getting to windows 1st load screen, maybe several times, it can get to windows sometimes then reboots before the desktop finishes loading, sometimes it can get windows loaded and sit there without using it and all's fine, then I go to load a web page and then it reboots again. Sometimes after all this rebooting it may decide to work with no problem for a few hours till I shut down normally.

Rarely a blue screen will appear with a stop error with a different code most times. Most times there is no blue screen.
When selecting "Disable automatic restart on system failure" it still reboots with no BSOD.
Tried getting to safe mode a few times, works sometimes, other times it reboots as the screen with the drivers are loading. Twice now after crashing on the safe mode driver screen an error has occurred where it says the registry file is missing or corrupt, then the only way to get it going again is boot to windows cd and repair.

The power supply blew up with a bang about 4 months ago but had been working fine with the new one installed,
I have tried 4 different sticks of ram, one at a time, in different slots,
Tried different video card,
Tried different HD with fresh format and windows installed, still rebooting. Different sata cable,
Checked all cable plugs,
Checked temps with "Open Hardware Monitor" for awhile, all temps were fine,

Any ideas what else I can try?? Is this a motherboard or CPU dying??


Gigabyte GA-N650SLI-DS4L
Intel Core2 Quad Q6600 2.4GHz
Windows Vista

Update; It was working ok on internet.
I went to use google earth program, and it crashed, (has been doing this every time I try and use google earth)

The "power supply blew up with a bang" may have damaged other electronic components. First thing I'd do is test it the RAM with Memtest86+

Version 4.20 for Windows direct download links:

• ISO for CD
  
• For USB Key

Let the Extended test run overnight. If you see any errors, try replacing the RAM and retest.


Software cannot be expected to run perfectly on flaky hardware.

After I replaced the PSU it was working fine for about 5,6 weeks.
I have already done a memtest with the original ram ( but not overnight) with no errors, but I tried two other sticks of good ram, one at a time out of a working comp and it still had the same problem.
I thought I eliminated ram issues??

Does it run ok off of a Knoppix Live CD/USB?

Use it for a while and see what happens. If it also crashes, that would indicate something other than software is probably causing the problem.

Check the capacitors on the motherboard to see if any are leaking or bulging.

This Motherboard has solid capacitors and all look fine.

I have Knoppix ready to run off USB so will see how that goes.

Ok, Have been running Knoppix now for about 24hrs, It has been fairly stable but has still rebooted a few times while using it and also a few times booting to Knoppix.

Booting to windows today has been the same as before, many reboots before windows starts (seems to get better as it warms up??), then finaly getting the desktop to show and finaly finnishing booting and just sitting there for say for 20min without doing anything, I go to use internet and cant even get a page to load before rebooting again.

2 times now at reboot it has run CHKDISK all on its own??

Quote:

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Ok, Have been running Knoppix now for about 24hrs, It has been fairly stable but has still rebooted a few times while using it and also a few times booting to Knoppix.

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Have you opened the case and made sure it is clean inside? and the fan blades are clean?
That sounds like possible overheating or power flux.

Quote:

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Originally Posted by VLCT

Ok, Have been running Knoppix now for about 24hrs, It has been fairly stable but has still rebooted a few times while using it and also a few times booting to Knoppix.

Booting to windows today has been the same as before, many reboots before windows starts (seems to get better as it warms up??), then finaly getting the desktop to show and finaly finnishing booting and just sitting there for say for 20min without doing anything, I go to use internet and cant even get a page to load before rebooting again.

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OMG(!) A computer should never suddenly shutdown|restart. Doing so can destroy files and/or scramble the file system.

Since yours is shutting down while running different Operating Systems, it indicates a hardware problem ... somewhere. To help isolate the culprit, I highly recommend starting with the absolute bare-bone basics:

• Motherboard (laying on a non-conductive surface [cardboard]),
• CPU (with cooler),
• RAM,
• PSU,
• Video card (if needed),
• Keyboard, and
• Monitor.
  
  (No drives or mouse needed yet).

Flip it on, go into the CMOS/BIOS Setup, reset it to factory defaults and reboot.

Go back into the CMOS/BIOS Setup and then let it just sit there ... overnight.

You'll know if it reboots because it would no longer be displaying the CMOS/BIOS Setup screen.

If it does reboot, the problem must be the Motherboard, CPU, RAM or PSU.

Let us know what you find out ...

Quote:

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Originally Posted by VLCT

2 times now at reboot it has run CHKDISK all on its own??

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When Windows is booting up it sets a 'dirty' flag (On).

When Windows is shut down properly, it deletes that 'dirty' flag (Off).

Up to this point everything is as it should be. It simply toggles back and forth between those two states and life is good. :)



When the computer shuts down unexpectedly, Windows does NOT get a chance to delete that 'dirty' flag.

So the next time the computer starts booting up, Windows sees the 'dirty' flag and runs CHKDSK to check for, and attempt to repair any damage to the files and/or file system. When CHKDSK is done, it deletes the 'dirty' flag and turns control back over to Windows.

Windows then sets the 'dirty' flag and continues booting up. Hopefully life is good again. :)

Ok I haven't had time to remove the Mobo, but did disconnect everything. Had CPU, RAM, PSU, Video Card, Monitor and Keyboard only, and a couple of fans running. Done the BIOS reset and let it run for 2 nights and all day today. Hmm NO reboots.

Ah ha, so far so good. (There isn't much strain on the PSU yet though).

Now boot Knoppix (USB flash) and see how she does.

1st boot to Knoppix restarted at load screen, 2nd boot got to desktop and still going fine.

(I upgraded Knoppix to 7.0.5 DVD and put that on the USB :)) Was using it last night for about 1hr with a couple of reboots.

Hmm im starting to suspect the PSU as well. Its lucky to be 4 months old, its a WideTECH PS-550TM 550 Watt. The old one was a 500 Watt.

(Was just having a look at some old pc's Ive got lying around and one has a 500 watt PSU with one power connetor that suits the SATA hard drive, may give that a go and see what happens.)

Quote:

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Originally Posted by VLCT

1st boot to Knoppix restarted at load screen, 2nd boot got to desktop and still going fine.

(I upgraded Knoppix to 7.0.5 DVD and put that on the USB :)) Was using it last night for about 1hr with a couple of reboots.

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It should never reboot by itself. In fact, older, solid versions of a *ix OS (like Aix 5.x) will run for years without a reboot, (on proper hardware of course).

Quote:

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Originally Posted by VLCT

Hmm im starting to suspect the PSU as well. Its lucky to be 4 months old, its a WideTECH PS-550TM 550 Watt. The old one was a 500 Watt.

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Strongly recommend investing in a quality PSU. Off-brands are simply not worth the trouble. It's like playing Russian Roulette with your hardware.

1st TEST, Well I just tried the other PSU, nothing has changed, was using Knoppix with no problem, 2 reboots at load screen though.

2nd TEST, Only had the main Mobo power conneted, and the TEST SATA HD with fresh format and install, same thing, few reboots, did get to windows, (I have no internet connection to that pc at the moment so I couldn't test it on the net) so I played around in windows and done a few things and caused a reboot.

So looks like back to the drawing board??

Is "the other PSU" known-good, or is it the "power supply" that "blew up with a bang"? :eek: (Flaky PSU's can destroy other hardware in your computer).

If it is known-good, then my next guess would be that either the motherboard (or something else) is occasionally shorting out against the case (or something else), or, the PSU that "blew up with a bang" did some damage to something on the motherboard.

Yes this PSU is "known-good".

The one that blew up was dead after that, I had a look inside that one and it was burnt inside on the board where something failed.

So it looks like I will take the Mobo out and have a good look to see if anything is shorting. Maybe that PSU did some damage.

So the CPU could cause this type of thing as well? Is there a way to test this before I pull it apart with something like Prime95??

Yes, I suppose a damaged CPU could cause a reboot but damaged CPUs are rare. More often than not, if it's not the PSU, it's usually the Motherboard or RAM.

After removing the old Mobo I had a good look at it, on the under side of the board where the PCI Ex16 slot is, up one end under a magnifying glass I could see some cracked solder on 2 or 3 of the pins for slot.
Also the slot was not straight on the board anymore, it was leaning down at the locking pin end (same end as the cracked solder)

So the new Mobo is back in the case now, after testing on the bench for 2 days, and its working all good now.

Love good news! :)