How can you tell if your GPU needs to be reflowed/reballed?

[Pretzel]

My Thinkpad T42p just started acting funny this morning (after owning it for 5.5 years) -- The screen suddenly started displaying red pixels all over the desktop. I could still see my desktop without any real problem, but there were all these red dots. I thought maybe the LCD was going bad, but I hooked it up to an external monitor and the same red pixels were there, too.

Rebooting the PC reveals that the BIOS screen is a little screwy, visually. In Windows, sometimes the red pixels change and there is a textured checkerboard pattern across the screen. Nothing really bad, but still bothersome. If I twist the case gently, just right way, I can get the visual aberrations to go away. But of course I have to hold the case like that.

Is this a good description of the GPU coming unsoldered from the mobo? Or is it something else?

[rkawakami]

Welcome to thinkpads.com!

Your description sounds exactly what one would expect to see when the GPU has started to come loose. Case flexing making the problem come and go is the common failure mode. The artifacts on the screen can be dots, bars, blocks, shadows, checkerboards, repeating defects in color and/or images. About the only other thing which could cause something like that on your LCD would be a cracked LCD ribbon cable. But seeing as the video problems also show up in the external monitor, that points to the GPU or video memory.

[Pretzel]

Hey! Thanks for the welcome and the confirmation.

Guess I get to try the "solder reflow" trick now. Or send it out to be reflowed. (Probably the latter, although a small part of me wants to try it myself.)

Cheers!

[poshgeordie]

I can confirm Rkawakami's diagnosis - it's a typical symptom adn the GPU does need reflowing.

Regarding doing it yourself it's a very precise process and you may be lucky and succeed, but personally I'd not risk it.