Laptop freezes when unplugged. Why?

April 26, 2005 10:19 AM

Why does my laptop freeze up a few minutes after the power cable is disconnected?

If the computer is running on wall-power and power cable is then disconnected, which sometimes happens accidentally, the computer will freeze up within a few minutes unless I notice and quickly reattach the cable. If, however, I boot the computer without the power cable connected, it runs fine on battery power until running out of juice.

Could this be a driver issue? I'd very much prefer not to have to mail it in for repair, even though it is still covered under warranty. In fact, if it's definitely a hardware issue that I can't fix on my own, I'll probably just deal with it as is.

This is more or less the laptop I have. It came with no operating system installed and I installed Windows XP (Professional) followed by the drivers included on the laptop manufacturer's CD. Each driver had to be selected and installed separately if I remember, so I guess it's possible that I simply missed one.

posted by nobody to computers & internet (5 comments total)

Two questions:

1) What brand/model of notebook.

2) Did you install any APM drivers?
posted by furtive at 10:21 AM on April 26, 2005

It's a Sager laptop from pctorque.com. The model number is 4380-V

(Display: 15" SXGA+ LCD, Processor: 3.2GHZ P4 800 FSB/Hyperthreading, Video: 128MB ATI Radeon Mobility 9700(M11), RAM: 1024MB 400DDR (PC3200), Hard Drive: 60GB 7200RPM, Media Drive: 8x DVD+- combo drive with DVD+R DL, Network Card: 10/100/1000 NIC, Operating System: No Operating System, Battery: Primary Li-ION battery pack, Warranty: 3 year warranty- under $2,000(Warrantech))

Can I check to see if I've installed an APM driver? (I had to google 'APM' to see what it was).
posted by nobody at 10:40 AM on April 26, 2005

My guess is that you may actually need to update the BIOS which does most of the work with Advanced Power Management (AMP)*. You can get most of these updates via the company's website.

Another possiblity is that you have a bad powersupply that is sending a slight under/over charge to your laptop, thus when it get's unplugged, the laptop gets confused and locks up.

*Note if there is an update I STRONGLY recomend you back up anything you don't want to lose, sometimes a BIOS update will create a need to do a fresh install of Windows.

To sum up: Let's eliminate a few possible variables. Do you have a spare power supply or battery? If so you may want to see if it is a specific combination of powersupply/battery causing the problem. As that would determine the bad part. If you are resonably sure that the powersupply and battery are ok, then I think your suspect is the BIOS.
posted by Numenorian at 11:20 AM on April 26, 2005

Does it only hang after you haven't been using it for a few minutes? If so, it's probably a problem with the suspend function. You're best to just turn that bugger off.
posted by krisjohn at 7:27 PM on April 26, 2005

krisjohn: That was the first thing I tried. It actually crashes a few minutes after being unplugged even if I'm in the middle of typing.

Numenorian: A friend has an equivalent power-supply and battery. I'll try testing my computer with hers over the weekend.

Thanks for the help so far. If anyone has any other suggestions/ideas, do chime in. If updating the BIOS forces a full windows reinstall, I'd rather leave that to the very last resort. (doesn't windows activation involve a phonecall now?)
posted by nobody at 9:00 AM on April 27, 2005