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Question

Computer Restart Problem !

Nov 10, 2015 8:03PM PST

My computer is restarting randomly ,frequency of restart is random (varying from a few hours to a day)
Strange thing is that the computer did not restart at some other location.The only difference was the power cable (which i already replaced) and the power supply from Mains AC power at that location. (New APC 600VA UPS already installed at my location giving backup and switching instantly to Battery mode in case of power cut.) Moreover, Inverter of 800 VA is also installed with inbuilt UPS feature ON.
I have already checked the current PSU in different location ,it's working fine. I tried to run the computer on different power point / wall jack but after around 20 hrs it restarted again.
Now, I have disconnected the hard drives and running the machine in BIOS only. I still need a day or two to check the recurrence. It has been very frustrating and annoying and also 1 of my hard drives have got bad sectors and delays due these restarts.

Kindly suggest possible cause and fix.

Discussion is locked

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Clarification Request
Tell more.
Nov 10, 2015 8:09PM PST

Make, model, age. If new let the maker fix it.

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Computer restart problem !
Nov 10, 2015 9:36PM PST

It's an assembled desktop computer. Specs as below:

Operating System
Windows 7 Home Basic 64-bit
CPU
Intel Core i3 530 @ 2.93GHz
Clarkdale 32nm Technology
RAM
Kingston 4.00GB Dual-Channel DDR3 @ 665MHz (9-9-9-24)
Motherboard
Intel Corporation DH55PJ (XU1)
Graphics
DELL ST2220M (1920x1080@60Hz)
Intel HD Graphics (Intel)
PSU
Corsair 550V
Storage
931GB Seagate ST31000528AS ATA Device (SATA)
1863GB Seagate ST2000DM001-1CH164 ATA Device (SATA)
Audio
Realtek High Definition Audio
Peripherals
HID Keyboard Device
Device Kind Keyboard
Device Name HID Keyboard Device
Vendor Hewlett-Packard
Location USB Input Device
Driver
HID-compliant mouse
Device Kind Mouse
Device Name HID-compliant mouse
Vendor Logitech
Location USB Input Device

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Ouch.
Nov 10, 2015 10:12PM PST

I see a lot of dated parts and ... Seagate drives. Try removing the extra HDD for now.

Open the case cover for max cooling. But it's quite old. I don't expect it to be flawless in operation.

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Correct !
Nov 10, 2015 11:10PM PST

You are right , it's around 7 years old now. However, I am already trying to run it in BIOS only and removed the extra drives from the machine.Lets wait and watch if this comes out to be related to hard drive.

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update !
Nov 10, 2015 11:17PM PST

Just now the computer rebooted again in BIOS mode. Hard drive were not connected, this means hard drives are not a cause of reboot , now need to find other power related cause.

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update 2 !
Nov 11, 2015 1:44AM PST

I am trying to run the PC now on a power point which is not receiving power from Inverter because there are a few points in my room which are receiving power directly from inverter(Su-Kam I800VA Multiple Battery) and some points are not. Besides this the APC 600 VA UPS is installed in the current setup.Lets rule out Inverter also and then We will junp to components as you mentioned in order PSU,Motherboard and CPU.
Thanks for the reply.

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Did you?
Nov 11, 2015 8:45AM PST

1. Do the canned air cleaning?
2. Replace all heatsink compounds throughout the PC?
(not negotiable on this old gear. it dries and dies.)
3. There is a suspect in the PSU due to age. On old gear I'll slip in a new PSU with +100 more Watt rating as a test. After that I call it a board. Can't be sure without swapping them.

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Partially Did!
Nov 11, 2015 10:19AM PST

Did air cleaning and there is no dust or clogging .CPU heatsink thermal paste reapplied and I do not have a spare PSU , I guess I have no option but to send to some repair workshop where the fault can be found.

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And the other heatsinks?
Nov 11, 2015 11:15AM PST

On such machines you'll find them on the north and south bridge chips, some GPUs and such. At 7 years, it's a top to bottom all over refurb to check it out.

->> I didn't mention a system killer but here's a google for what else I inspect for on motherboard, cards and inside the PSU. Read https://www.google.com/#q=bad+caps

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Clarification Request
can you better explain this?
Nov 11, 2015 11:20PM PST
"Strange thing is that the computer did not restart at some other location."

I've looked at all the recent readings like CPU-Z and all that you've done. It all looks good.

"(New APC 600VA UPS already installed at my location giving backup and switching instantly to Battery mode in case of power cut.) Moreover, Inverter of 800 VA is also installed with inbuilt UPS feature ON."

You have a 600w UPS which should match the Corsair PSU on the computer without problem and that all seems sufficient for the computer. Your video card (ZOTAC) doesn't use more than 50w power either.

Yet, that odd statement comes back to me, "computer did not restart at some other place". Did you also use the UPC at that other place?

I don't believe there is a problem with the computer itself. There does seem to be a power problem where you normally have it's power coming from, and whatever that problem is, seems to get past your USP.

I'm not clear on what 800w Inverter you refer to is used for. Typically an inverter refers to converting DC power to AC. How does this inverter figure into this? Inverters often use square sine wave actions due to being a electronic method of mimicking alternating current, which doesn't always work with devices which use or expect to be using a normal wave pattern.
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Inverter/UPS
Nov 12, 2015 6:07AM PST

Inverter 800VA is there in my room in case of power cuts as they happen quite frequently where I live. That also has a UPS mode which is ON. Besides that APC 600VA UPS (bought a week ago)is present. At other location some other UPS was tested. It could be a chance that the computer did not restart for two days there. I have also tried with other UPS but same problem.Also tried without APC UPS but used Inverter inbuilt UPS and again same issue.
Memory test is passed with Memtest86 run from bootable USB. Tried without hard drives and it still restarted after a few hours.Temperatures are normal in various software utilities like(speedfan,CPUID ,etc). I have reseated all the components /cables possible.No overheating of the ICs/ components observed. Can it be motherboard issue?

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Yes. Aging of the electrolytic capacitors for example.
Nov 12, 2015 6:58AM PST

We try to save the machine but at some point old parts will haunt the machine.

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Rob mentioned "bad caps"
Nov 12, 2015 10:40AM PST

It's more a problem on older motherboards than you have, but could also be a problem on newer ones, just less likely. However you obviously have some real electric supply issues going on there and surges and resulting spikes can even blow the newer "solid" type (vs electrolytic) capacitors too.

Heard any firecracker noise, or a pfffffttttt hiss, or a funny unusual smell that lasted maybe less than a minute or two? You can google bad caps, but they will usually show the electrolytic types.
So, here's images of blown solid capacitors. They tend to blow off the top more than out the bottom.

What does a capacitor do? It takes in the power after it's been converted from AC to DC, but still has some "ripple" effect in the power, and passes the power through an electrolyte from one electrode to another. This for lack of better imagery sort of fuzzes out the remaining AC ripples giving a cleaner DC current, and also helps in controlling between some lesser power surges. You can find some better explanation in a google no doubt. A capacitor is like a high capacity battery, pretty much accomplishes the same function of both storing some power and smoothing out the current. Too much "ripple" in the supplied current can cause sensitive electronic components to not work correctly. It's the last step in the power process before the power is turned loose to the other motherboard components.

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"once its age gets into the 5-10 year range, all bets are
Nov 12, 2015 10:54AM PST
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will recheck !
Nov 13, 2015 11:48AM PST

No noises,smells around.As a first look no caps seems to be bad but i will recheck again !

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It's more than bad.
Nov 13, 2015 12:35PM PST

It's the aging issue of electrolytic caps. We are way past the design life so even if it say rebooted once a day, that may be as good as it gets until we replace boards and PSUs.

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Please take a glance of the motherboard !
Nov 15, 2015 2:02AM PST
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does video card have a power port on it?
Nov 15, 2015 11:32AM PST

If so, I don't see a power line to it. You need to carefully check the tall black cans with the silver tops. From the image the tops look OK, but they can also lift up off the motherboard when they blow out through the bottom. Those are capacitors, aka "caps" for short. Some of those are also in PSU units.

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Answer
Run Memtest86
Nov 11, 2015 7:47AM PST
" also 1 of my hard drives have got bad sectors and delays due these restarts."

Bad sectors of course corrupt data, but another way is failing RAM which writes back data incorrectly to the hard drive. It's the one place proper error checking doesn't occur in today's desktop computers. So, first make sure the RAM is running correctly.

You will get a boot CD, DVD, or bootable USB program that allows to run the memtest. You can get that alone, or download an Linux distro ISO file which includes the test, which can be burned to CD or DVD. By booting to it, you avoid having hard drive problems interfering in the process,

http://www.memtest86.com/

If it passes the RAM as OK, then can go forward from there.
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Memtest86 passed!
Nov 11, 2015 10:16AM PST

Memtest86 test is OK and no memory related errors found.

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After insuring not overheating
Nov 11, 2015 10:24AM PST

open a command box and run

chkdsk /f /r

and it can take all night. That will check the disk for bad sectors and correct what it can. After it's finished, reboot and check your Event Viewer for an entry giving the results of the chkdsk.

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Rules out Hard drives !
Nov 11, 2015 11:22AM PST

I booted the machine in BIOS without attaching hard drives and the computer still rebooted so I guess we can rule out hard disk.

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Answer
RAM
Nov 11, 2015 7:52AM PST
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Did not noticed
Nov 11, 2015 10:15AM PST

I did not noticed that as I got the computer assembled by someone 7 years back and it has been working ok for me until now.Can you tell me what multiple should be set for these to work at max capacity. However, this is secondary conecern, the primary issue is that the machine is restarting randomly and RAM test(memtest86) is OK.

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At 7 years there is work that must be done.
Nov 11, 2015 10:19AM PST

Heatsink compound for example is well past its prime so that is my usual since along the way I'll clean it all and get to check the heatsinks are on proper too. Figure 2 dollars of material which makes you wonder why folk resist such work.

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ditto
Nov 11, 2015 10:22AM PST

Heat is next area to check if RAM is OK.

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Will check it !
Nov 11, 2015 11:26AM PST

I will definitely check other heatsinks also but when i run the temperature monitor softwares then I see all temperatures(motherboard,CPU,Hard drives) are normal.Can't those temperatures be trusted.

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All temp monitors I know don't measure
Nov 11, 2015 1:47PM PST

The north and south bridge, and all the chips on the machine. In fact I've see temp monitoring apps cause reboots. Go figure.

I still wonder why techs resist a 2 buck charge for compound and such. Maybe it's good news for sales?

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Agree.
Nov 11, 2015 1:57PM PST

I don't take these temp measures as gospel. The work in hand being so cheap, why Not?
Dafydd.

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queries !
Nov 11, 2015 10:47PM PST

Are there any utilities to test PSU/Motherboard ?

Also what would be the ideal Vcore voltages for the CPU?