T40 display problem

[psychocandy]

Started out with the screen being a bit fuzzy and then switching off and on if you moved it (sort of like a loose connection). Now its just got a large black and white stripe.

Is it worth changing the screen cable first rather than buying a whole new screen? Or will I need one of these as well?

How difficult is it to change the screen cable?

[Johan]

I am sorry, but I believe I may have some bad news for you... your GPU (graphics processing unit) on your motherboard may (very well) have come loose from the PCB; this is a very common error with T40/T41/T42's (and fewer T43's) - see e.g. the sticky T42 shuts down when i move it. There are at least a couple of places in England (and nearby, in Germany) where this can be fixed at a reasonably cost - see e.g. the thread T42 monitor falls out when touched (and the links pointed to therein).

In the USA, there is especially one place which repair T4x motherboards quite cheap; see the thread Superior Reball GPU Fix. Finally, if you are brave you may try fix the motherboard yourself; see the sticky at the top of this forum: GUIDE: Reflow GPU fix. If you search on YouTube you will find quite a few more (but most a bit less professional) "do-it-yourself" guides.

Examples of the look of garbled LCD's owing to the (in-!) famous "loose GPU" problem may be seen in the ThinkWiki-page: Problem with garbled screen pointing to these images.

Johan

[psychocandy]

I am sorry, but I believe I may have some bad news for you... your GPU (graphics processing unit) on your motherboard may (very well) have come loose from the PCB; this is a very common error with T40/T41/T42's (and fewer T43's) - see e.g. the sticky T42 shuts down when i move it. There are at least a couple of places in England (and nearby, in Germany) where this can be fixed at a reasonably cost - see e.g. the thread T42 monitor falls out when touched (and the links pointed to therein).

In the USA, there is especially one place which repair T4x motherboards quite cheap; see the thread Superior Reball GPU Fix. Finally, if you are brave you may try fix the motherboard yourself; see the sticky at the top of this forum: GUIDE: Reflow GPU fix. If you search on YouTube you will find quite a few more (but most a bit less professional) "do-it-yourself" guides.

Examples of the look of garbled LCD's woing to the (in-!) famous "loose GPU" problem may be seen in the ThinkWiki-page: Problem with garbled screen pointing to these images.

Johan

Johan,

Thanks. I'm afraid to say that some of those pics do look similar to what my display looked like.

Although it got better/worse/changed when I moved the monitor on the hingle which is why I assumed it was a loose connection or something.

[poshgeordie]

Sorry to hear of your problem. I agree with Johan in that it does sound like a graphics chip problem.

I've sent you a PM.

[psychocandy]

Sorry to hear of your problem. I agree with Johan in that it does sound like a graphics chip problem.

I've sent you a PM.

Nick,

I've replied to your PM. Thanks.

Just one question I asked in the PM which might be of interest to forum members. How do I know 100% that it is the GPU chip being loose and not something else like faulty cable, loose connector etc?

[poshgeordie]

It's a good question and it could also be a bad connection or faulty cable; however fairly overwhelming evidence does point to the graphics chip problem.

As part of the fault finding process you should try the following:

1. Power the TP down and lift the keyboard out of the case but leaving it connected to the motherboard.
Disconnect the little thinkpad ribbon cable connector from the motherboard
Press down on the graphics chip - labelled ATI and is under where the thinkpad ribbon cable ran to it's mobo connector.
Power up the TP. Do you now have a good screen display?
If Yes it's a graphics chip problem.
If no, it still could be but move onto step 2.

2. Plug in an external monitor. Power up the TP; is the ext screen display OK?
If No, repeat with step 2 pressing down on the ATi chip again.
If now Yes on ext mon, then it's most likely a graphics chip problem
If No move onto step 3

3. If you have a known good display and lcd cable assembly, try those.
If Yes then it's a lead / connector / display problem. Carry on substituting each component until you find the faulty item.
If No then still probably a graphics chip problem.

I realise there's a fundamental problem with step 3 in that you need spare cables and display so this could be difficult to do.

Before I reflow any graphics chip I carry out these steps because I need to know the probable fault before I commence with any work.

Sending you a PM in a second!

[psychocandy]

It's a good question and it could also be a bad connection or faulty cable; however fairly overwhelming evidence does point to the graphics chip problem.

As part of the fault finding process you should try the following:

1. Power the TP down and lift the keyboard out of the case but leaving it connected to the motherboard.
Disconnect the little thinkpad ribbon cable connector from the motherboard
Press down on the graphics chip - labelled ATI and is under where the thinkpad ribbon cable ran to it's mobo connector.
Power up the TP. Do you now have a good screen display?
If Yes it's a graphics chip problem.
If no, it still could be but move onto step 2.

2. Plug in an external monitor. Power up the TP; is the ext screen display OK?
If No, repeat with step 2 pressing down on the ATi chip again.
If now Yes on ext mon, then it's most likely a graphics chip problem
If No move onto step 3

3. If you have a known good display and lcd cable assembly, try those.
If Yes then it's a lead / connector / display problem. Carry on substituting each component until you find the faulty item.
If No then still probably a graphics chip problem.

I realise there's a fundamental problem with step 3 in that you need spare cables and display so this could be difficult to do.

Before I reflow any graphics chip I carry out these steps because I need to know the probable fault before I commence with any work.

Sending you a PM in a second!

Nick,

Thanks.

Understand that pressing down on the chip can make it work temporarily. I'm a bit confused about the external display though.

Why do you need this step? Am I right in saying that if the chip is loose etc even the external display wont work? The chip powers all display doesnt it? (both internal LCD and external display).

Although I guess if the external display is still problematic then it rules out a faulty LCD/connector?

BTW. My laptop is a T41. I'm still unsure whether its financially viable to have it repaired or just buy a new one and sell the parts of the old one on ebay. (Wife has got her eye on an acer netbook !)

Although I must admit with it seemingly being such a widespread problem I'm surprised that IBM/Lenovo can get away with not repairing for free even outside warranty period. Surely in this instance, sale of goods act specifically fitness for purpose should apply (after all it is, in effect, a design fault)?

[poshgeordie]

Nick,

Thanks.

Understand that pressing down on the chip can make it work temporarily. I'm a bit confused about the external display though.

Why do you need this step? Am I right in saying that if the chip is loose etc even the external display wont work? The chip powers all display doesnt it? (both internal LCD and external display).

Although I guess if the external display is still problematic then it rules out a faulty LCD/connector?

BTW. My laptop is a T41. I'm still unsure whether its financially viable to have it repaired or just buy a new one and sell the parts of the old one on ebay. (Wife has got her eye on an acer netbook !)

Although I must admit with it seemingly being such a widespread problem I'm surprised that IBM/Lenovo can get away with not repairing for free even outside warranty period. Surely in this instance, sale of goods act specifically fitness for purpose should apply (after all it is, in effect, a design fault)?[/quote]

This is what's going on when there's a graphics chip problem.
There's a fundamental graphics chip design flaw in that localised hot spots develop inside the chip assembly causing local warping.
The ball grid array (BGA) solder balls then break off the motherboard around the hot spot.
This usually only becomes apparent when the TP is moved and the broken joints are separated, causing the display to go off or distort etc.
The fault therefore lies with ATI the graphics chip manufacturer rather than Lenovo, and you'll find the same problem in any laptop fitted with the same ATI chip family - Apple iBooks for instance are even worse!

With this in mind, the 'standard' test for a detached graphics chip is to press down and power up the TP. About 70 - 80% of the time it'll display on the screen correctly.
Pressing down on the chip can remake the separated joints.

The reason for mentioning the external display is to make sure that you don't have an internal display or cable problem. If everything's OK with an external display then the problem points to an internal display problem rather than a graphics chip problem.
Also, and a lot rarer (I've personally never come across it) is that there are separate video outputs to the internal and external displays so using an external display simply checks the BGA leading to the external display - probably ignore this in practice.

But you are realistically correct in saying that if the external display is still problematic then it rules out a faulty LCD/connector.

I don't want to comment on buying a new Acer versus repairing your T41, but I do know that the T4x's are a lot more robust - under the 'hood' a lot of new laptops are so poorly made that I'm surprised they last as long as they do. Don't be blinded by the external 'bling' !!