T42 Screen Turns on and off if Moved, Only when Plugged In

[cooljw]

I have a wierd screen problem with a 3 year old T42. The screen turns on and off repeatedly when the laptop is plugged in, running on AC power and being moved slightly. But what is perplexing me is that the problem does not occur in any other situations:

When the laptop is plugged in but not on AC power (AC adapter is unplugged from wall) the screen is fine.

When the laptop is in its dock and running on AC power via the dock the screen is fine - even if I shake the whole setup around.

When the laptop is unplugged and running on battery the screen is fine.


Originally I thought the problem must be some kind of loose connection exacerbated by the AC adapter being plugged into the laptop, but the fact that I can't duplicate the problem with the AC adapter plugged into the laptop when the AC adapter isn't sending power makes me believe otherwise.

Anyone have any ideas?

MOD EDIT: Moved from X6x series to T4x.

[jamesd058]

I just bought a T42 via IBM Re-Certified Program and immediately started having this screen problem. I was using the AC Adapter plugged into the wall. Every time I touched, poked, tapped, or moved the screen forward or backwards it would go "BLACK" for a second, and flicker off & on if I moved it continuously. I called the Warranty Service number at IBM and they immediately sent a courrier to pick it up, and said I'd get a complete replacement.

What I'd like to know is this a known issue and is there a [permanent] fix? This is for my aging Mother who is finally going to try the World Wide Web experience. If I get a replacement machine that will eventually succumb to the same problem I want to try take action pro-actively. The warranty is only 3 months on these Re-Certified machines.

Thanks.

[cooljw]

UPDATE TO MY PROBLEM: After reading through the Sticky'd "t42 shuts down when i move it" thread I figured that maybe my screen problem is related to the GPU being loose after all - until now I didn't think it could be since my screen problem only occured when plugged in.

So tonight I opened up my T42 by removing the keyboard and palm rest. I discovered that I have the heat sink that covers the entire GPU (seems like most folks with the problem have the fully exposed GPU?). I then turned on the computer and the screen was all screwed up - actually not the shutting on/off problem but static and fuzz. But, applying pressure on the GPU with my finger pretty much remedied the problem so I figured that I must have a loose GPU after all!

So I cut up a business card and an old credit card and stuck them on the area above the GPU (to put more pressure on the GPU) and then put the T42 back together. The problem is gone! Hopefully it will stay gone.

Stupid laptop is only a few months out of its 3 year warranty too. Seems like these T4x series really are time bombs due to the GPU issue.

[jamesd058]

I just called the support number and sent the unit back. A replacement took two weeks! I guess I should leave it turned on until the 3 month warranty is up. Thanks for all comments.

[bblesser]

Having discovered that I had the badly soldered GPU chip in my T42, I researched the topic and solutions. Here is what I found.

Diagnosing the problem as the GPU is often uncertain because depending on which pins are intermittent, the symptoms change. In my case it was relatively easy. While I had the usual crashes, hangs, and failures, occasionally I also had a screen "rip" with corrupted video that could not have come from bad software, i.e. it was analog in nature. I was lucky to get a clear manifestation of the problem, and being an engineer, the implications were clear.

To the best of my knowledge, the problem originated in a particular time period with many manufacturers, including IBM, Dell, and Apple, when they were forced to quickly adapt to the European RoHS requirement of no lead in solder. They had no experience with the new formula and some devices simply did not solder well. It was a hidden defect because the solder joints would only break when mechanical and temperature stress was applied, as in flexing the frame.

At least for me, the magic solution was to contact, Dale Miedema at Superior Reball and Rework, 1-847-426-3012, or customerservice@superiorreball.com. For $50 he turned a piece of landfill junk T42 into a fully functioning laptop. While he has had some bad press from some customers, I found him helpful, friendly, cooperative and most importantly, very competent. I treated him with politeness and respect (which is always a good choice).

I hope this helpful to those who also have the GPU problem in T4x laptops. It beats adding to the toxic landfills.