T40: bottom 1/3 of LCD is goofy, sometimes

[John H]

Sometimes colorful lines appear horizontally and sometimes vertically in the bottom third of the LCD. Now, this morning, no problem at all.

So, I suppose it's an intermittent connector, like for the cable, so I should open it up and jiggle and squirt Contact Cleaner.

Can anyone confirm? Point out a more specific connector?

[ajkula66]

More likely a GPU issue, given that you're getting the lines...

[John H]

GPU issue? Sounds like there might be a lot of info here. Where should I start?

And what's the GPU? Graphics Processing Unit?

Can I replace it with a new one easily and cheaply?

LCD looks OK when T40 is cold, but as it heats up the bottom third starts to tear and then turns into many fine lines.

[BeeJayEmm]

John,
The best place to start is with the sticky. Yes, you got the acronym right. As you'll read in the thread (and elsewhere, if you search), the only solutions are motherboard replacement or reflow of the solder attaching the GPU to the motherboard. Good Luck!

Brian

[SMA]

My guess is that this is NOT a GPU error, but a failing LCD panel.

Naturally, guessing can be helpful but knowing is better.
To find out - attach the machine to an external monitor and see if the error is also there. I guess it is not.
If the error is also present on the external monitor then it will most likely be a GPU error else I do believe that it is a LCD panel error.

If you do not have an external monitor - go get one.
There are so many CRT monitors being thrown away these days that getting one should be possible at almost no cost.

Am I right in guessing that you are having a T40 with a SXGA+ screen?
If in doubt, look at the bottom of your machine and find the type/model number.
The number would be something like 2373-xxx, where the last 3 characters are the interesting ones.
Having the type/model number we can look it up and see if it has a XGA or SXGA+ screen.

[BeeJayEmm]

Perhaps someone more knowledgeable can confirm or deny, but I have read here that an uncorrupted image on an external monitor does not necessarily mean the GPU is good. I remember reading in other threads that a bad GPU can affect the internal or external or both.

[ajkula66]

That is correct. You can have a failing GPU and absolutely no signal on LCD, but perfectly good output to external monitor.

The reason I'm saying that this is likely a GPU problem is the randomness of the symptoms, that the machine gets wacky unpredictably. And that we're seeing horizontal or vertical lines. Dying LCD usually shows white areas, or pixelated lines that won't go away, regardless of what one does.

I'd try running PC-Doctor on every component of the system and see where that gets me...

[SMA]

What I meant to say was that if there is a good picture on an external monitor, then in this particular case, the chances that this is a LCD panel error will be higher. I did not try to put up a general rule.

I do have a colleague at work which is using a T41 with an SXGA+ screen. That machine has the exact same problem as described in this topic.
Not that it helps much, but I have seen this error live today.
My colleague is almost always using his machine with an external monitor, so he actually does not care much about this error.
Unfortunately there is no chance that I will ever be able to open up that machine, since it is company owned.