t40p 2373-g1g video display problem

[heiner99]

hi all,

My t40p has since a week a display problem. The display is unreadable. There are troubles on the screen like stripes - look the picture:


I come to the conclusion, that the MB is defective, because also an external monitor shows these effects.
There is a workaround for the problem: if I disconnect the machine from any power and wait some hours it starts up with no problem. If I turn off the machine now and start it again - I have the problem again. So I have again disconnect any power and wait some hours and so on ...
I suppose that there is something wrong with the video memory because in the defective state it shows 16 MB video memory and 32 MB otherwise. Normally it should have 64 MB video memory.
Unfortunatedly the machine is out of warranty since two months. The MB was changed 4 months ago, due to the usb 2.0 problem.
I know its hopeless, I have to buy a new MB! But maybe anyone has an idea to solve the problem, e.g. a program which do a deeper refresh of the video memory and the gpu than the BIOS and driver does.

thanks

heiner

[agarza]

Upgrade to a T41 or T42 motherboard. Or even better a T43 mobo.
I'm not sure but I think T40 MB are more prone to have defects on the long run

[christopher_wolf]

Welcome to the Thinkpad Forums

It does indeed sound like a MB problem, although perhaps slightly different from the ordinary. Does the screen change if you pick it up gently from one corner? That is a sure sign of a hardware problem with the GPU on the T40.

There really isn't a program that would help given that it also shows up on the boot splash screen, a mobo replacement is your best bet.

[heiner99]

thanks for the answers,

the screen didn't change if I put the TP on the edge. I removed also the keyboard and the fan and pushed slightly with the finger on some places of the mobo (e.g. gpu) but nothing changed. I supposed that there is anywhere an insulate contact, but hmm very mysterious...
I will do the next days some additional test, perhaps I can get more information about the problem

The upgrade to a T43 mobo is a good idea, but as I read in other threads there are some disadvantages. The main point is, as I understood, that I cannot use the T40 cpu on the T43 mobo (its for 400 MHZ bus and the T43 mobos have 533 MHZ bus), correct me if I'm not true.

So an upgrade to a t42 mobo will be the best. But there's an additional question. If I put a mobo which needs the "fan assembly (long) M10", can I use the old "fan assembly (long)" with it.
Is the sole difference that the fan assembly long M10 didn't have the plastic sheet at the gpu area ?

thanks for hints

[tyito2000]

Had almost the same problem. My T41 mobo was replaced 4 minths ago. However, my T41 sometimes displays a garbage screen at POST. After quite a bit of research, I now believe the Centrino logo on POST screen causes these sort of problems. You should check your wireless mini pci card and run diagnostics at DOS level. Also, I am still looking into the CMOS battery providing memory registers in EEPROM to retain the centrino logo setting at POST. This would be a proprietary use of CMOS to support Intel Centrino validation. In other words, you should check and make sure your wireless card is the exact part number specified by IBM. Also, you should test the wireless card in DOS, And lastly, I would recommend replacing the CMOS battery.

[heiner99]

The centrino logo - thats a new idea. I started the TP without the wireless card - but the problem persists. I also removed the cmos battery for one night, but there was no change in the behaviour of my T40p. It seems that there was only the clock data lost, some other data like Boot-up sequence stayed. So the mobo wasn't completely resetted. Running diagnostic at DOS level is a good idea, I will do it soon

[tyito2000]

The odd thing about the centrino logo is that it actually checks the Intel Boot Agent before POST to determine whether to display the Centrino logo on the first IBM logo screen. Since that is the case, I believe that the Intel Centrino memory registers are held in EEPROM and maintained by the CMOS battery. Remember this Centrino check would most likely hit the EEPROM before POST or BIOS. Therefore, I believe that Intel's Centrino check for a genuine Intel wireless card is proprietary and executes before BIOS.

[zandric]

Recently I had similar problem with my T42...

After heavy wetdown of running TP I had similar lines after cca 1 min of working on battery. When TP was on external power. everything worked fine.

Chnanging MB solved problem.

I am afraid that yiou are right - MB has to be changed.

All the best

Zoran

[beeblebrox]

The problem is the graphic chip. It looks like one or some of the BGA soldering spots have disconnected from the motherboard (problem with BGA chips).
Very similar problem with the A22p series, same picture on the screen.

You could run the test for the graphics chip to see which banks are disconnected.

Solution: try to solder the chip ( I don't know if there is access from the other side) again with a very fine tip.

[rkawakami]

If the problem is indeed a bad solder connection on a BGA packaged part, then don't bother trying to use a regular soldering iron. There won't be any access on EITHER side of the board since the contact balls (the "B" in BGA) are on the bottom side of the package. About the only thing that will work is a hot air re-flow SMT (surface mount technology) soldering station, not your usual item in stock at Radio Shack.

Attempting to put heat onto any of the traces on the opposite side of the video graphics chip (or any other for that matter), will only cause that trace to lift up off of the board. Unfortunately, with the industry going over to SMT there isn't much one can do anymore to fix these types of problems.

[heiner99]

So, the problem seems solved. I used in the BIOS settings the Setup Defaults. Now the problem didn't occur anymore. The graphics memory is shown with 64 MB again - how it should be. [censored]! why didn't I have this idea formerly.

[heiner99]

Unfortunatedly the problem wasn't solved. So I looked something around and found the following threads:
http://forum.thinkpads.com/viewtopic.ph ... c&start=30
http://www.thinkwiki.org/wiki/Problem_w ... led_screen
http://video.google.com/videoplay?docid ... 0fix&hl=en

Very helpful was the video. Exactly this procedure I have done and it worked. I was a little carefully and needed three attempts before it was solved (I used the Air Gun for shorter time than needed and the distance was too high. But finally it worked. With an 400 C Airgun 20 cm away for 2-3 minutes.
Nevertheless it casts a [censored] light on the quality of the thinkpad mobos. Mine had an age of around 4 months (it was changed because of USB problems). I tried to get help from IBM but without success. It was my misfortune that the mobo get the problems.
But in my opinion the solution with the Airgun shows that the mobo wasn't built carefully.

heiner