Tech: PC goes black then reboots - unasked

Subject: Tech: PC goes black then reboots - unasked
From: katlaughing
Date: 20 Dec 07 - 02:10 PM

This past week my monitor has suddenly gone black without provocation on my part, that I know of. The first time it didn't come back up until I'd turned it off at the tower, then started it back up. That happened once. Since then, it's happened about three times, each of those times it has rebooted itself. No warnings, no reports, nothing.

The only thing I can think of that I've done differently was copy a ton of files to the Recovery drive instead of the external. I realised what I'd done when it kept warning me the D drive was getting low on memory and removed them to the external and thought maybe that had caused the problem, but here it is, come back again.

I have all of my updates installed, virus check, ad aware and all of that running regularly and have kerio firewall, so I don't think it is any of that variety. Of course, who am I to know?

Any of you have some idea and/or advice?

Thanks,

kat

Subject: RE: Tech: PC goes black then reboots - unasked
From: Bert
Date: 20 Dec 07 - 02:23 PM

I would first try to narrow down the problem by trying your computer with a different monitor.

Subject: RE: Tech: PC goes black then reboots - unasked
From: katlaughing
Date: 20 Dec 07 - 02:35 PM

Ah, you think it could be the monitor? Will do that, thanks.

Rog was wondering if it was a power driver going out?

Subject: RE: Tech: PC goes black then reboots - unasked
From: Brendy
Date: 20 Dec 07 - 02:35 PM

Failing that, try going into 'Safe Mode' at startup (CTRL+F8?), and head for the Control Panel - Display - Settings - Advanced - Monitor - Properties - Driver
See what driver is installed, and if your copying of files has upset some balance there, you have the option to 'Roll-Back' to your last Monitor Driver.
Your graphics card and driver is also accessible from this area.

'System Restore' may be another option...., but I am no expert on these matters....

Hope you get it sorted, kat.

B.

Subject: RE: Tech: PC goes black then reboots - unasked
From: beardedbruce
Date: 20 Dec 07 - 02:44 PM

If the disk drive is nearly full, it might be running out of swap space. The disk with the operating system on it should have the selected swap space PLUS about 15-20% ( of the total disk) EMPTY for proper operation. It is a good idea to keep 20% open on all disks, actually.

The reboot indicates it is not a monitor problem.

Subject: RE: Tech: PC goes black then reboots - unasked
From: Nick
Date: 20 Dec 07 - 02:53 PM

If it has it look into 'manage' if it is XP or similar.

Riht click My Computer left click Manage and look at the Event logs - there will likely be a clue there as to what is doing it. If it's an earlier operating system I can't remember what it available

Subject: RE: Tech: PC goes black then reboots - unasked
From: JohnInKansas
Date: 20 Dec 07 - 04:37 PM

If it's a CRT monitor, it's sort of a "characteristic" for older ones to begin to run a little hotter, and if they start running too hot, to shut themselves down. Often - or at least sometimes, the termal limit switch in the monitor won't reset until you power off, and then restore power, even if the monitor itself has cooled down enough to run again.

Regardless of what monitor type you have, the internal graphics card (even if it's an "integral-on-the-motherboard-interface" has much the same problem. Power dissipation with the attendant heating has surpassed the problem of keeping the CPU from burning itself up with some of the newer graphics cards and some new ones have very elaborate cooling systems. Even with older ones that aren't doing all that much fancy stuff, with age and decrepitude one may begin to get hotter, or the thermal safety may start tripping at a different (lower) temp - but either way the monitor will shut down.

Either of these probably will require a hardware replacement - either the graphics card or the monitor, and sometimes both. A simpler possibility is that you're just seeing "Power Management" in action.

Many computers made even more than ten years ago included the possibility of full or partial shutdown after a set period of inactivity. They called it "green machine" design. In the early days of this subsystem, it was seldom turned on by default; and it's not unlikely that a lot of people have it and don't know it. Around five years or so ago, it became common for most manufacturers to turn it on; but lots of people shut it off the first time it bothered them and forgot it was there.

Newer machine almost ALWAYS arrive with full power management features all turned on. There usually are several modes:

An "Idle Mode" (names may vary, sometimes called "Standby") may just shut down hard drive motors and the monitor signal. Usually there's little delay to turn back on when you move or click or hit a key, and people often don't realize that this is a separate mode of operation.

A "Sleep Mode" puts things down a little deeper, and coming out of sleep mode for some machines may look like a reboot - or may actually be what amounts to a "warm" restart.

(Sometimes the different names have been used in different orders of turnoffyness.)

Most Power management systems can also be set to "Shut Down" after a certain time of idleness. In this case, you literally do have to "Cold Boot" to get back up.

In recent Windows OS versions, you should find the settings at Start|Settings|Control Panel, double-click on "Power Management."

During the "transition years," as this kind of use became more popular and more used, some builders incorporated "proprietary" utilities, so in Win versions prior to Win2K or WinXP you may find "PMS" (Power Management System - not that other thing) almost anywhere on your machine - sometimes rather cleverly hidden. (This was especially true for some now-ancient laptops.) In WinXP you should find it in Control Panel as indicated, even if the builder included another management utility.

John

Subject: RE: Tech: PC goes black then reboots - unasked
From: Nick
Date: 20 Dec 07 - 06:44 PM

Obvious thing to say but if it's doing something weird make sure you have your important data backed up

Subject: RE: Tech: PC goes black then reboots - unasked
From: katlaughing
Date: 20 Dec 07 - 10:25 PM

Thanks, fellahs. My Rog and I are going to try some of those things this weekend. I do have everything important saved to the external drive, now.

John, I don't think it is the go to sleep mode as it does it when I have been actively working on it for awhile, not when there is no activity. You may be on to something with the overheating, though. It is an older monitor, probably five years. Also, I'll have to clean out the cat hairs again, the Siamese likes to groom and toast himself on the monitor.:-)

Rog thinks it may be the power supply, though last time that happened it just went dead and that was it. This is just weird in that it seems to be so random. I think that would indicate the overheating.

Nick, we did the events thing the other day after it happened and didn't see anything untoward.

Thanks, again. I'll let you know what we find.

kat

Subject: RE: Tech: PC goes black then reboots - unasked
From: Andrez
Date: 21 Dec 07 - 12:46 AM

The idea of trying an alternative display is a good one that will help you isolate where the problem is occurring. That way you can save a lot of time by locating the issue in the box or the display.

Another option is that I can send you a troubleshooting flowchart in pdf format that will let you follow through several troubleshooting processes in a systematic fashion. PM me if you like with some email details and I'll flick the flow chart through.

Cheers,

Andrez

Subject: RE: Tech: PC goes black then reboots - unasked
From: Mysha
Date: 21 Dec 07 - 04:58 AM

Hi,

Let's see:
* The computer actually resets, so it's not a monitor issue (except if it's a laptop).
* There are no error messages afterwards, so it probably did go through shut down of its own; it's likely not a power problem.
* There are no error messages before, so it's probably not out of disk space. (It's still is a good thing to check the hard disk, later, as when you unintentionally filled it you may have fragmented disk space, which would mean disk access may have become slower.)
* If it really does boot each time (Check that you see the start-up screens.), it's not power management.
* I, myself, am not near. (I'm rather sensitive to electric current, and judging by the weird behaviour of some machines, the feeling in mutual.)

Generally having a classroom full of computers to keep an eye on, I see things like this most weeks. There can be all kinds of curious causes, but the most common by far is overheating. Most often, this can be remedied by opening the machine and clearing the dust out (All the dust: if necessary, take out the power supply and vacuum its inlets and outlets.)

Block of experience, gained the hard way:
If you remove dust, try to use a vacuum cleaner, or a brush. If possible: Don't wipe with cloth as the friction can build-up electrical charges large enough to fry a chip. (Do check for brush hairs afterwards.) If you're the kind of person that always has sparks flying when dressing in synthetics: make sure while working inside the computer you touch metal regularly to discharge, again to protect the chips. Before you open the computer for this, disconnect it from the net completely (that means all cables, even the cables to the monitor and the modem etc. that are themselves connected to the power). And, of course, make a back-up, even of that one file you just downloaded or wrote, because recreating it may turn out to be harder than you expected.

I hope this helps with the Gremlin hunt.

                                                                Mysha

Subject: RE: Tech: PC goes black then reboots - unasked
From: nutty
Date: 21 Dec 07 - 06:10 AM

Overheating can also be caused by a fan failure or misfunction.

Subject: RE: Tech: PC goes black then reboots - unasked
From: Richard Bridge
Date: 21 Dec 07 - 11:16 AM

Do not clear dust by blowing with your mouth. I once cooked a motherboard AND powersupply bigstylee that way, And two hard drives and even teh flopppy drive!

Subject: RE: Tech: PC goes black then reboots - unasked
From: Bill D
Date: 21 Dec 07 - 12:00 PM

Gee, Richard...maybe mouthwash would help....











*ducking out the door*

Subject: RE: Tech: PC goes black then reboots - unasked
From: Nick
Date: 21 Dec 07 - 01:24 PM

Defective fan or something stopping it turning? Have seen that cause regular reboots

Subject: RE: Tech: PC goes black then reboots - unasked
From: Bee
Date: 22 Dec 07 - 09:16 AM

This problem surfaces with my old computer when too much cat hair and dust has built up on the fan. Try cleaning the fans and the interior of the case as much as possible and see if that helps. I'm no expert, but keeping an old computer running at all has made me aware of the overheating problems caused by dust. As others have mentioned, if it is rebooting, it isn't likely a monitor problem.

Subject: RE: Tech: PC goes black then reboots - unasked
From: katlaughing
Date: 22 Dec 07 - 11:28 AM

Thanks, folks. We've slept in today and not got to it, yet. I can hear the fan in the hard drive, so I don't think it is that. I do think it is likely the monitor is getting too hot due to Himself, Kipling the Cat. Will clean it out, sans blowing with my mouth (eeewwww!) and see what doesn't happen, I hope!