Red dots on screen with T61/NVidia 140M

[rutteger]

This is something to which I fear I know the answer - assume the GPU is on the way out.

For the last few days on my T61 running windows 7 have been seeing red dots on the screen, both LCD and dual external on dvi and vga. Also getting the occasional driver crash which manifests itself as a brief blank screen followed by windows redrawing the screen and bringing up an error (the details of which I don't have to hand).

Annoyingly the laptop is a couple of months out of warranty, had the heatsink replaced for the second time at the end of last year.

Anyone had any luck reballing the GPU as per the issue on the T4x? Or is it soon to be new laptop time? This is my work machine so it just needs to, er, work!

One thing to add, the warranty expired end of Nov 2010. Might I be able to extend it with Lenovo and get a repair that way? Or am I out of luck on that one?

[RealBlackStuff]

You are most likely right.
Contact Nick at Reflow Repairs (see my sig).

[rutteger]

Interstingly found this thread on the lenovo forums (via here) > http://forum.lenovo.com/t5/T61-and-prio ... td-p/46469

Given it's only a few weeks out of warranty and given the recent work completed on it might give lenovo support a try. Anyone had any luck doing this in the UK? Looks like people in the US have had luck.

[miamicanes]

Not sure whether it's due to The Big Nvidia Problem, but my desktop PC has a low-end nVidia 8500GT graphics card from ~2007 with more or less the exact same problem you describe... every now and then, I'll get little clumps of red pixels that look like they were sprinkled around. They're mostly stable (they remain where they were when I move windows around and the display changes), have good days, have bad days, and seem to be particularly bad whenever an app involving full-screen Java is running (or has run recently). I first noticed it around 1.5-2 years ago.

If there's any good news, I don't think the problem on my card has ever really escalated beyond "annoying"... but you might be able to get a new mobo out of it anyway, just because I doubt Lenovo is scrutinizing incoming boards that much. The downside is that it doesn't occur (on my PC) consistently, so you might have a problem getting them to believe there's something wrong if they DO check unless you have some way to take high-res photos of the screen when it happens.

Other observations:

* It has been observed with three different displays, two connected via DVI, one via VGA.

* I saw it before I added my second monitor, but even now it seems to mostly affect the primary display. I have, however, seen it affect both simultaneously on a few occasions. I don't think I've ever seen it affect only the second display.

* Full-screen Java seems to trigger it, but once triggered, it seems to remain.

* Occasionally, I'll "almost" think I can see some kind of pattern when there are multiple clumps, but they're never quite identical, and I've never seen anything that literally looks like rubber-stamped similarity aligned to a grid.

* The individual red pixels do seem to drift in brightness, but not collectively as a group, and independently of whatever's going on with the real bitmap they're supposed to be displaying.

Sigh. If nothing else, someone should use this debacle as an example to show the EU why its quest to banish lead from solder is causing more real harm to both the environment and consumers worldwide than just living with it as a necessary evil.

[MnR]

Hi,

You might want to check the fan on your video card. I had my fan go out on my 8500GT. The temp climbed slowly and the the brightness would flicker.Then No signal. When I took the card out the fan had seized and a cap had blown.

I replaced the cap and the fan. I also removed the heatsink, Clean the chip and applied Silver paste to it. After all that I found that the chip had blown from high temps.

MnR

[rutteger]

@miamicanes that does sound like the issue I'm having. Good to hear it's been relatively stable for you.

@MnR fan/heatsink was replaced only a few weeks ago under warranty. Pretty sure the unit also cools the GPU.

The red dots although slightly irritating are certainly liveable with. Just obviously concerned given this GPU reputation it's going to pack in soon. I do often have the laptop running 24/7 as a desktop machine, although the screens are off overnight. Since I've posted yet to see the red dots. Was going to try upgrading to the nvida released windows7 driver, currently running lenovo released one, see if that helped.

[miamicanes]

I doubt whether it will help. I've had the dots on two different motherboards (one with Athlon64-X2/4200+, one with Core2Quad 9400) under both Vista/32 Ultimate and Windows 7/64 Ultimate. It's definitely hardware.

Personally, I think it might be a RAM issue -- most likely, one or more poor solder connections that mostly work, but have flaky connections. Almost certainly due to lead-free solder. The problem is that lead-free solder doesn't stretch when cold the way lead-based solder does -- it just breaks, or separates from the board. It also forms whisker-like crystals that can bridge adjacent pads.

In a very real sense, with lead-free solder, you end up with solder connections that, 20 years ago, would have all been classified as cold joints and gotten a board pulled from the assembly line. Now, it's the legislatively-mandated norm. It's fashionable to blame China for electronic devices that fail in a year or two (as opposed to legitimately blaming China for devices that fail within a week or two), but the blame really lies with governments that force manufacturers to use solder that just plain doesn't do the job it's supposed to do as effectively as leaded solder did. The sad irony is that every year, millions of devices now end up making premature trips to landfills due to misguided laws supposedly intended to save the earth.