IBM thinkpad T42 blank screen issue

Hi everyone,
First post here. I come to for advice: I have been having issues with my IBM Thinkpad T42. The problem is with my LCD display. The computer turns on fine, goes through the IBM screen and windows login, but if I accidentally move it slightly, the screen goes blank. If I do a hard restart, it works fine but again, depending on if I move it slightly or move the table slightly, it goes blank. I am pretty sure the computer is working fine otherwise, but I can check that by attaching it to an external monitor when I go to work on Monday. Any idea what the problem is with the LCD?

I have been doing some research, and it seems like this is a common problem among Thinkpads. Different fixes have been suggested: It might be an inverter problem (it might be loose or needs to be replaced), or it could be a bulb issue. Since it works sometimes and not other times, I think its a connection issue. Any help with this issue would be great. Thanks.

 

Welcome to nbr,
it sounds like the ribbon cable on the back of your lcd is coming loose.
What you need to do is power the system off, and remove the screen bezel. Take the lid apart, so that you can get to the back of the lcd.
Once you get this far, you need to locate the ribbon cable which connects the lcd to the system motherboard. You need to remove that cable from the back of the lcd. Do so gently.
Once removed, grab some rubbing alcohol and a q-tip to lightly clean the connections. Only use a small amount of rubbing alcohol on the q-tip, and dry excess before reconnecting.
You should clean both ends of the port, the one on the back of the lcd and the cable itself.
Than when everything is dry, reconnect the cable, and put a piece of tape over the cable, so that the cable cannot become removed again.
Than reassemble the lid and power up.
Your problems should be all fixed.

I hope this helps,

good luck

K-TRON

 

thanks. I am going to give this a shot tomorrow morning. Will keep the thread updated.

 

Update: I opened up the bezel, and got behind the LCD screen. There is a ribbon connected to the LCD screen, and the ribbon eventually splits into 2: One end goes to the system motherboard, and the other goes to the green chip located right below the screen (the inverter).

I did as you suggest, and it seems like applying rubbing alcohol to the connection between the LCD screen and ribbon has only solved half the problem. Now, if I move the screen, it doesn't go blank, but if I lift it, it sometimes does. This suggests to me that this is definitely a loose connection problem, but I am not sure where. Could it be the inverter? Any other suggestions would be really helpful. Thanks.

 

Interesting enough, when i lift up the computer and it goes blank, it restarts the computer automatically. Just an observation.

 

Have you looked at the other end of the cable?
(The part of the cable which physically connects to the motherboard)
They may be loose, which is causing the connection issues.

Your inverter is working fine. The only thing it can be is a connection issue or a short which is caused by something loose moving when you move the computer.

K-TRON

 

The part of the ribbon cable that attaches to the motherboard looks okay from the outside. The copper wire is taped to black colored tape that then goes into the motherboard. Maybe I will try to get a hold of a camera and post some pictures. Do you think pictures will help?

 

No, STOP looking at the LCD assembly. Your problem is widely known in thinkpads.com Forums. What your laptop is suffering is the famous 'Loose GPU'. You can either send your motherboard/whole laptop to reball/reflow the GPU chip on your motherboard. You can actually see it for yourself: Grab a piece of thick paper and place it just below your keyboard so that it touches the GPU die. If you move your laptop, it would not show the blank screen you comment.

Basically what is happening here is that the GPU chip solder joints had become loose and so when you move the laptop, the GPU loses contact with the mobo resulting in no input signal.
You could fix your laptop by yourself actually, just follow this guide:
http://forum.thinkpads.com/viewtopic.php?t=57021

OR make a post there, I'm a member there (agarza), and many of the people there are knowledgeable, to my opinion the best Thinkpad forum ever.

 

thanks. I will make a post there as well, but I will definitely stick around here as there is a ton of great info to be learned here as well. Thanks for the tip.

 

Wow, great post T30power, I never would have guessed that the integrated graphics card would have been coming loose. A friend of mine has a T43 which looks very similar to the T42 on the inside, and when looking at his X300 built in gpu, it looked like it couldnt move.

feynmix, well if all of the connections are fully connected and clean, than this must be the answer. I am glad cleaning the connections helped a bit, but that may have been conincidental, since this loose gpu issue is actually a known problem

K-TRON

 

I have the same issue but my screen goes blank when I disconnect power. The screen is blank/black but you could see the images and the sound is still active. The battery is in good condition, and lasts about 40 minutes. Does anybody have any ideas? Thanks in advance.