So, another turn of PC problems.  Since yesterday, it's been powering off suddenly.  Not exactly powering off, as lights remain, but screen goes black, HD stops running and no keyboard response.

It happened agan today as soon as it loaded Windows.  I opened the case panel and the fans are running.  Leaving the case open however seems to have stabilized the problem.

So, it looks like it's an overheating.  But since the fans are running, could it be some problem in the power pack?  Would it shut down the components like I describe, or would this happen only if the problem was in the processor refrigeration?

I could be some sudden, very short voltage drop. It was happening pretty often to me before my power supply died. At least, the replacement is not so expensive...

Ivan,
I was suspicious of the power supply, although I've never had a problem with this particular component in any of my PCs. On the other hand, video card is always an issue for me (I think I've posted to other "help" questions in the past year, all related to it). Let's see if I am right, having removed it.

Now, how do I make WinXP understand I don't have a generic monitor? I have already downloaded the monitor's drivers, but WinXP says I don't have that hardware.

melastmohican,

Just for clarification, my current video card is not connected to the power supply. I understand that modern models have a "fansink" which requires this connection, but mine has a heatsink. Is that what you meant?

Anyway, I remember I made sure I had enough power capacity plus a safety allowance.  But marine environment destroys electronics so easily....

melastmohican,

Just for clarification, my current video card is not connected to the power supply. I understand that modern models have a "fansink" which requires this connection, but mine has a heatsink. Is that what you meant?

Anyway, I remember I made sure I had enough power capacity plus a safety allowance.  But marine environment destroys electronics so easily....

If your video card doesn't get power from the power supply, how does it get it's power? Everything plugged into your mother board gets it's power from the power supply, unless you have some external box and some really unusual system?

Sounds like an overheating problem by the way, but I've also seen computers with memory problems, suddenly shut down like that. Re-boot and they run fine again. Wait a couple of hours and they run fine. Overheating or memory issues.

Some people are answering with laptop problems, which are commonly caused by overheating. Blocked vents, fans that don't cool enough, processors that are being asked to do too much. Same for a desktop without proper cooling. A heat sink just tells us that the Mfg. knows there's a Temperature problem and tried to make it better.

Get an additional cooling fan! They are cheap insurance. It will help reduce the processors overheating. It could help reduce the hot video card. It can keep your power supply from overheating. Some computers have three fans in order to keep the system cool enough to operate without shutting down. Even if you spend a small amount and it doesn't solve the problem, the additional fan is not expensive and good protection in a hot climate, where overheating can be a constant problem.

Make sure the inlets and vents are not blocked by cables and wires, or things on your desk. Air flow is important.

If you know someone or can find a free memory check test, where it checks your chips, please do that. Mixed memory a bad chip, or conflicts can cause a computer to suddenly shut down.

Power Supply getting weak. If it suddenly smells very bad and smoke comes out, there you are. (funny but true...)

Sounds like overheating to me as well. If it's an oldish machine get the case, fans, heatsinks and PS carefully blown out with clean dry compressed air ( not tyre inflation air at the local garage) at the lowest pressure possible or failing that careful brushing and vacuum will do. Re-seat the heat sink on the processor using a tiny smear of thermal compound.

One thing that can give all sorts of weird faults is the memory. On some boards the memory modules seem to "creep" out over a period of time. Make sure they're pushed hard in. You need to put the machine on it's side if it's a tower case. Power off (obviously) and give the memory quite a hard push straight down into it's slot to make sure it's seated. Make sure the video card is seated properly too. If you suspect the processor is running too hot than you can download something like Motherboard monitor, or Speedfan (Google them) to give the board temperatures. One other thing it could be is a cracked motherboard which has a track that opens up when the board gets above a certain temperature. Pretty rare though as I understand it. Sometimes repairable if you have a friendly electronics guy handy, but probably better to swap the board.

Oh and Hi everyone. I don't think I've posted here before although I've looked for ages.

Is this what the 'marine environment' you wrote about does with your computer? With wet salty air? Unbelievable!
When your motherboard looks the same way as on the photo I am amazed that there is anything inside left that works at all!
But now I see what you mean: This way every computer will get destroyed in a short time.
The problems you have: When it looks like this, it can be everything. The motherboard, the videocard, the powersupply, everything...
Rust and erosion can damage computer electronics very quickly.
Is there absolutely no way to place the computer in an environment with a more dry air ? A special air controlled closet or something?

No, normally there will be no conflict when you can see more than one monitor installed. Same with a mouse, usb-stick or whatever.
A 500 watt powersupply should be enough for a computer that is already a few years old. It did work well in the past, did it?

But what is very, very dangerous to a computer is rust and corrosion. A computer needs to stay as dry as possible. Salt water in the air is the worst you can have.
This link: http://oldcomputers.net/corrosion.html, shows the effect of corrosion on a motherboard. The small lines get connected by rust and corrosion. A kind of short-circuiting. This image is about an old motherboard. On newer boards the lines are smaller and even closer to each other with even quicker damage as a result. The solution that is given will not work today with the newer motherboards.
When your motherboard looks like it is seen on your photo, it is most likely that there is corrosion on the battery too. Perhaps it is leaking. With more damage by the chemical fluid.
When there is corrosion on the connectors and the slots on your cards, your cards (videocard, soundcard) will not work properly for not having a good connection (contact) to the motherboard. Same with the connection of your harddisks.

If (of course I cannot say for sure) here lays the problem, you can try this solution: carefully disconnect every connection in the computer and connect it again. Do this a few times with every connector. It is temporary of course, there will be new corrosion. So you have to do this on a regular base.
Never shut down your computer by day or night, so it will stay as dry as possible by having all the time almost the same temperature.
Try to find a way to blow warm, dry air through your computer. Don't put your computer on the floor. The combination with dust in your computer that gets wet is even more dangerous.

About the mobo's videodriver:  Modern boards often have a videocard 'onboard'. Means that the chip is mounted on the board. You can see it if there is a connection for a monitor on the backside of your motherboard. Thereby there is also a slot to connect a videocard of your own choice if you want. The computer switches automatically to the one you use. If the drivers are installed of course. When installing the mobo videodrivers you can connect your monitor to the motherboard directly. The onboard chip is using a part of the memory (only when in use). If there is corrosion on the memory strips and/or their connection you can have troubles too. An unstable powersupply is also still an option.

Perhaps this solutions to avoid damage are not possible at all. Then the only solution is to buy a cheap computer and buy a new one when getting problems with the old one.
New computers are fast enough at least for the first one or two years. When it becomes too slow or damaged: buy a new cheap one.
Personally I have no 'environmental' problems, but this is the way I act too. I build the computer by myself, so the only things I need are a new motherboard, new memory and sometimes a new powersupply. All other things can be reused. At least one or two times. And except the need of reinstalling the software...

Sometimes you can have corrosion and for a while all seems to work well. It all depends on where the corrosion is. But sooner or later it will be over! And repairing is useless then.

Well, it has become a novel!  Perhaps there's something in the story that can be useful to you. Hope so! Good luck!