strange t41p problem

[flensr]

Maybe some of you guys have heard about this problem.

My t41p will work fine for hours or even days, but then it'll crash and for the next hour it sometimes won't even boot. I suspect a hardware problem because sometimes typing on the keyboard, or using the mousepad, or even adjusting the screen angle will cause the crash. Or tapping the area over the hard drive will kill it. Sometimes it won't even get to POST for multiple reboot attempts, followed by a successful boot that will leave the computer working fine for another whole day.

I'm in a dirty location (Iraq) so I first suspected dust, but I took off the palmrest and keyboard and found minimal dust in there. I cleaned it out and it again worked for an hour, then crashed (black screen, hard drive light blinks for a few seconds then nothing until hard reset). I thought maybe something was shorting, and found that the two wireless lan antenna posts were touching the metal backplate underneath the palmrest, so I used a bit of tape to insulate that, but that didn't help either.

Anyone know of what else might be the problem? I've had this thing for 7 years including some hard travel and replacement of the cpu and heatsink/fan unit, and it has never done this until about a month ago when it started acting weird. I thought at first it was drivers but now it seems to happen with as little provocation as walking on the floor next to the desk it's sitting on. Or it will work for days without any problem...

Any idea? Any common failure points? I was thinking the display ribbon, but there are so many things it could be, I didn't want to take it apart again until I had a better idea what might be wrong.

Thx in advance...

 

[JesseKnows]

There are known issues with the T4x (I believe T43 is OK in that respect). The motherboard's soldering of large chips, mostly the video chip, becomes flaky. Either through thermal expansion/contraction, or by flexing when the unit is held by one edge.
Start at http://forum.thinkpads.com/viewforum.php?f=2 and see the sticky threads at the top.

You can confirm by removing the keyboard and firmly pressing the video chip (ATI, approximately under the upper touchpad buttons) into the motherboard with a finger. You can then try to boot and see the effect.

Specifically for you, the duct-tape fix is to put some firm padding above the video chip, and have the keyboard press the pad onto the chip and improve the contact with the motherboard. I have done that with folded cardboard. Note my experience is with T41 which has a smaller heat sink that doesn't cover the video chip (Radeon 7500). It may be more complicated with the T41p where I believe the heatsink and the heatpipe cover also also the ATI FireGL, but the principle is the same.

You may need to experiment - you don't want the pad to be too thick because the keyboard is not very rigid and you don't want to deform it. You may also experiment with a very thin plate of rigid material (maybe steel or magnesium) under the keyboard and above the cardboard, to spread the pressure around the bottom of the keyboard and reduce its deformation. You also do not want to deform the heatsink out of contact with the video chip, and definitely not break the heatpipe.
Good luck, keep safe!

 

[flensr]

Thx, that seems to make sense. I'll try putting in a spacer over where the heatsink covers the gpu.