Thinkpad suddenly freezes up.

[NautTboy]

What could the reason why pc would sometime freeze on iSERIES 1400?

I swapped HD and still freeze, again not all the time, just sometimes.

I thought might be the ram, so I'd replaced that, still freeze.

Could it be Windows XP? I haven't try previous windows.

[ArtShapiro]

I'm completely unfamiliar with that product, but as nobody else has chimed in:

Heat is often the cause of sporadic failures. Is your fan operational? Is it easy to get to the fan to see if it is caked with dust and lint?

Does the situation improve if you put one side of the computer on something like a book, to allow air circulation underneath, and perhaps blow a household fan on the computer as an experiment?

Art

[mgo]

What could the reason why pc would sometime freeze on iSERIES 1400?

I swapped HD and still freeze, again not all the time, just sometimes.

I thought might be the ram, so I'd replaced that, still freeze.

Could it be Windows XP? I haven't try previous windows.

I did a quick check at http://en.wikipedia.org/wiki/ThinkPad and that machine is fairly old...having been discontinued in 2000. That could mean the fan is not working or the cooling system is clogged, as ArtShapiro stated in his reply. Try using a vacuum cleaner or canned air to blow the vents out. Take the keyboard off if you can and gently hold the fan so it will not spin wildly and be damaged during this air blasting procedure....or just use a little very gentle vacuum at the vents for a couple of seconds to prevent hard spinning of the fan.

[SMA]

Could be a leaking capacitor on the motherboard.

[Kaervak]

Does it happen with the AC adapter plugged in? How about when there's downward pressure applied to only one side of the laptop? A couple years ago I worked on a i1500 that had random freezing issues when on AC power. Turned out that the DC powerboard had cold solder joints on the DC plug that when an AC adapter was plugged in, the power connection would spike/drop enough to get the system to hard lock. After taking apart the laptop and resoldering the DC jack, the laptop worked just fine. That might be what's causing the freezing issue.

[NautTboy]

Thanks for all the info given. The fan still blows strong. The bottom of pc where the cpu sit is just has normat heat, not extreme or anything.