R51 intermittently reboots, especially on movement

[HFat]

Hello everyone,

My R51 is unfortunately having issues. It spontaneously reboots, constantly when used normally (typing on the keyboard, moving it to make room for other stuff and so on) and occasionally when leaving it totally still on its own table... sometimes several times in short sucession and sometimes not at all for a day.
Is it a known problem?
Any ideas as to the cause of the problem and how to fix it? It's out of warranty of course.

Even if it's fixable, it would probably be better if I moved on to a new laptop. I'm not sure I'll stay with a Thinkpad because I'd like to have one of the virtualization extensions and the Thinkpads which have VT are quite expensive in my country.
I guess I could buy a Thinkpad from the US and replace the keyboard... does anyone know what would happen in case I need to use the warranty then?
Or I could buy a cheap AMD-based laptop with virtualization support... the battery life would be poor but I don't need a long one that much. I would not even have considered it a while back but I planned to keep using this Thinkpad a while longer (I've only been using it for 3 years and a half at most) and I'm more open to trying other brands after this disappointment. The fast Ultrabay hard drives aren't such an exclusive feature now as well given that one can get eSATA through an ExpressCard. It would still be nice to have though.
Please excuse me for this off-topic rambling. I'll take any advice you'd be kind enough to offer.

[underclocker]

If you have an R51 with an ATI video chipset, you're probably looking at a loose GPU, the T4x's have the same motherboard and problem --> http://forum.thinkpads.com/viewtopic.php?t=33952

A forum member fixes these motherboards --> http://forum.thinkpads.com/viewtopic.php?t=48458

Good luck.

[HFat]

No, I've got Intel graphics.
Maybe someting similar is happening anyway but I haven't noticed corrupted graphics at all.

[HFat]

I've got an update and some questions for you.

The problem seems to have improved somehow and I got no reboots while the laptop was sitting still three days in a row.
I tightened the screws and the laptop seems to have become more stable since then but using it like a laptop still makes it reboot way too often to be acceptable.
I tightened the screws several times and I've got the feeling I've tightened some of them too hard the last time because it tends to reboot when tilting the screen now, as if the whole thing was too rigid and I was forced to use too much force (and flex it too much). Then again it also seems the problem has become worse in general, as if using the Thinkpad like a normal laptop again made it less and less stable over time... or I may just be reading too much into random reboots. ;-)
If someone has a suggestion as to which screws I should loosen or something, please let me know. I may perform more aggressive surgery when I finally get around to purchasing a replacement.

Two forum members told me this Thinkpad has a loose GPU (I got a PM)... but how do we know that? It's not that I'm skeptical: I'd like to know how one can determine that based on the symptoms I described.
The PM suggested that I call Lenovo (why not IBM?) to tell them I have this widespread issue but I'm not sure how to make the case that this is indeed the issue I'm having. Is it even a widespread issue for the people who have an Intel GPU? And if I send them the laptop, I'm afraid they won't have enough patience to reproduce the problem as it's intermittent (although there are ways to trigger it, they are not reliable).

Also, if I ever decide to fix this thing properly myself (as opposed to selling it for parts or whatever), what parts do you think I should try to replace first (if at all)?

Thanks.

[ajkula66]

If you've got Intel graphics, you most certainly don't have a case of a loose GPU.

Having said that, your board may be going bad. I've had a R51 that somewhat resembled yours in behaviour, but have lost patience with it and parted it out.

Good luck.