Subscriber David Weisner wrote recently to advise that he had continuing PC shutdown problems that he was having difficulty diagnosing. David wrote back with some more information on his problem…
Thanks for getting back to me. However the problem is just another feature of the original problem you responded to. When I plug in any USB hard drive it causes the computer to instantly shut down. I purchased a new USB hard drive because I thought the other drive was bad but it had the same problems.
To recap, the first time I saw a problem was, when I plugged in the USB hard drive, it would click or beep repeatedly and I would see its drive letter appearing briefly in Windows Explorer and then disappearing.
Then eventually the letter stopped appearing entirely but the beeping continued.
I got a new drive and the same thing happened.
Then the new drive stopped beeping. When I checked USB devices when it was plugged in I could see that there was a Toshiba mass storage device but Windows Explorer still did not give me a drive letter.
Then when I plugged in the drive it immediately shut down the computer.
The latest problem is what I told you about, which is when I run a full scan but (not a quick scan) the computer does the same thing. I do not know how long it runs before this because I am out when the scan is running. It also happens infrequently when nothing much is happening but the computer has been on a long time.
I hope this helps you to guess at the source of the problem.
Based on my own experince, I wrote back to David that I still thought it was an internal hard drive, specifically C:, his drive that has Windows installed on it. I suggested that he make his backup and get his recovery disks ready. I can see all the symptoms happening if it’s the Windows drive.
Dave wrote back with an update — for a while, it seemed that he had solved the problem.
The powered USB port has allowed me to run both of the external hard drives that my computer would not recognize.
As for my computer shutting down, a thorough cleaning of a very dusty fan seems to have fixed the problem. I guess the circuit breaker was being tripped by heat buildup
Unfortunately, that message was still a little premature…
After all of the stuff with my desktop computer shutting down I discovered something. My power supply has a fan on the back of it but the fan is not spinning. My power supply feels really warm to the touch.
Would it be reasonable to assume that the fan not working is causing the power supply to overheat?
One odd thing about this is that the computer’s on light continues to be on even though the computer is shut down. Would this be due to the capacitors still having stored power in them?
David’s thought that a power supply fan could cause overheating, and the resulting shutdown, is exactly right. That’s what happens if the power supply gets too hot.
On the computer light staying on, that’s more of a stretch. The motherboard is live all the time — the power switch on the computer case is nothing other than a momentary contact switch to trigger the motherboard to wake up. That’s why the instructions say to unplug the computer before inserting/removing any cards, connecting any drives, or adding/removing memory, etc.
David recently wrote back to say that he’s now solved the problem.
I put a regular fan on the computer and it has not shut down since.
Now I will replace the non-functional fan.