T43p UXGA very Dim screen...tried almost everything

[BPRomine]

What a problem this has turned out to be.

The problem first started a few weeks ago when I unplugged my computer and took it to my office in the basement. The screen went dark. I have a very bright light on my desk and noticed that my screen was dark but still could see icons on the screen. I restarted my computer and it would come back for a few minutes less each time. When I used the lid closed off button the screen would come back perfectly to show the log off screen.

I did some research on here and found it best to start with the inverter. I tried one from ebay and one from IBM. Nothing. I found if I partially plugged the LCD cable to inverter it would come back perfectly for a couple minutes. I then purchased a new LCD. I tried it and still receive a dark screen.

I have since purchased an external monitor and it works great.

The last part to try is the cable assembly (91P6858). When I spoke with IBM the tech said he knew of an issue with a cable but before I could get a word in he transfered me to someone that didn't know anything and wanted to sell me a new LCD. How hard is it to replace the cable and are there instructions somewhere?

Can someone please help me? Thank you in advance.

[richk]

First, I assume the machine is not under warranty. (most T43s are still covered) Put the machine back together without the keyboard bezel and start it up. If the screen works, the button in the keyboard bezel is stuck. You can see if the button in the cable (right under the keyboard bezel button) is sticking. You can try to clean the contacts on the motherboard where the cable attaches. If you replaced the LCD, you must have removed and reinstalled the cable already, so I don't understand the "how hard" question.

[BPRomine]

Yes, the machine is out of warranty...by about 3 weeks.

Second, I tried the keyboard stick problem already to no avail. Great idea though.

The cable I'm talking about is the one that goes to the Motherboard. I have never taken enough of the computer apart to find the MB. I was thinking I need to replace the cable from the MB to the back of the screen. Any advice on how to get to the MB is welcome.

[richk]

It is actually easier to replace the panel if you remove the cable from the MB. You unhooked the difficult end first. Here is a link to the service manual which will answer your questions:

http://www-307.ibm.com/pc/support/site. ... MIGR-58791

[GomJabbar]

I don't know if new LCD panels from IBM/Lenovo come with cables attached or not, but several of us T4x user's have had to replace the panel to get the backlight to function again. If the others that sent theirs in to servicing had the LCD panel replaced, I wonder if the cable was replaced with it?

In my case, I bought a complete display lid which included the cable off of ebay. Replacing the complete display lid is not too difficult, you just need to take your time and be careful.

FTR, I had a XGA display in my T42. You might have difficulty finding a UXGA display used, as they are not so common.

Personally, I would be surprised if it was the cable. The reason I say this is because on my T42 I rarely ever closed the display lid. I would think that repeated flexing would be the primary cause of cable failure.

EDIT: Please post back with your results, good or bad. This information helps us to help others.

[richk]

Actually, I think the most common failure points in the cable are the switch or dirty contacts.

[BPRomine]

Here is an update on this issue.

I have replaced the cables, the inverter, and the LCD. None of this has made a difference. This is starting to sound like a MB issue. I have read a couple other posts that sound exactly like mine. If someone has any answers I would like to hear them. BTW, I have been using an external monitor since this problem started.

[Troels]

Hmm.. you're very unlucky. Still one suggestion.
Look closely at the LCD cable for broken wires. It is very easy to break the 90 degree joint at the part of the cable that goes to the inverter.
I have done so, and thus broken 4 wires in that 90 degree point, just by reinstalling the LCD and thus the backlight won't work unless i push the LCD cover in a special manner in a specific location.

I firstly thought the inverter was dead, so i replaced it at first. After i did the push on the LCD cover trick again, the connector on the motherboard began to smoke, so i quickly powered everything off again
No damage however, and a new factory fresh LCD cable fixed it.

[wearetheborg]

Here is an update on this issue.

I have replaced the cables, the inverter, and the LCD. None of this has made a difference. This is starting to sound like a MB issue. I have read a couple other posts that sound exactly like mine. If someone has any answers I would like to hear them. BTW, I have been using an external monitor since this problem started.

Well that sucks.

If you purchased the laptop with a credit card, it may still be automatically covered by warranty (through the credit card), see my sig.

[Brad]

I don't think there is much of anything else to try except the motherboard. If you have a spare motherboard I would try it.

If not I could lend you a working board to try.

Brad

[BPRomine]

Brad,

This is a very generous offer. I don't know if I have enough courage to replace the MB by myself. I guess I've taken apart everything else but still don't think I should take a chance. Let me know if you have suggestions.

Thank you!!!

Brian

[Brad]

Brian,

Send the ThinkPad to me and I will make the swap for you.

Brad