Pink lines on my R50e LCD display (Warning - pics)

[ilyes]

[edited text from the previous post]

Hi all,

I recently got my LCD display (on my 2 years-old Thinkpad) getting a bunch of horizontal pink (acutally, not white) lines drawn from the top to the bottom of the screen on a restricted block. The pattern of these drawn lines changes as I move the mouse cursor or windows (applications) on the (windows) desktop. It's really annoying.

I tried a lot of tricks, like running my laptop on AC and then only on batteries, changed the screen resolution, changed the bit depth, booted under Linux, etc. : I get those lines even on the boot screen (IBM logo). I'm pretty sure that it's a hardware issue, not software. Another thing, I connected my laptop to an external monitor through the VGA connector and I got a clean picture on it. The only reason (that probably caused this behavior) that I can remember is that I used my laptop during a trip on train and I remember everything got pretty much shaking badly.

Here is some snapshots of my LCD showing off the symptom (follow the mouse pointer) :






Alright, so that's it. Any idea guys? I already opened today (as described in the hardware maintenance manual from IBM) my laptop and reseated the LCD connector to the main board (I didn't open the LCD assembly). Nothing changed so far... Any comments, suggestions are really welcome!

Thanks in advance.

Best regards,
Ilyes Gouta.

[ilyes]

Updated. Please see the initial post. Thank you.

[ryengineer]

That's stuck pixels.

Try rubbing a cloth on that area, very gently. They normally go away by time though.

[ilyes]

Hi ryengineer,

Thanks for the fast reply!

So, is it really just that !? I really hope so. I'm having this issue for a week or so, now.

Does anybody know of any reason that would have caused such a phenomenon?

Best regards,
Ilyes Gouta.

[ryengineer]

It could result due to unstable transistor inside the lcd failing to provide power to the lcd or due to manufacturing defect sometimes.

[rkawakami]

A couple of possibilities as this does not look like the typical stuck pixel to me (those are usually a few pixels distributed around the screen in a random fashion).:

- loose connection in the ribbon cable from the motherboard to the back of the LCD
- damage to the driver transistors along the edge of the LCD
- loose/broken connection of the graphics chip (i.e., GPU) on the motherboard

The cheapest thing to try is the ribbon cable. Follow the instructions in the Hardware Maintenance Manual (HMM) for your system:

http://www-307.ibm.com/pc/support/site. ... 54932.html

to disassemble the laptop to get to both ends of the LCD ribbon cable. The connector on the motherboard is fairly simple to access. I believe that removing the keyboard and keyboard bezel will allow access to the ribbon cable connector. The hard one is the back of the LCD panel. Re-seat both ends (unplug and plug it back in) and see if that solves your problem. If not, then most likely there is a bad connection within the panel itself (not very possible to fix; replacement is about the only solution) or you have a problem somewhere in the motherboard (also the same type of "fix"). You can try putting some slight pressure along the edges of the lid (not the screen itself) and see if that makes the "stuck" pixels go away. That would indicate a problem within the LCD panel. Or try pressing the bottom of the laptop in various areas to see if the display returns to normal.

Twisting the base of the laptop (picking it up by one corner) can put enough pressure on the motherboard and cause some of the parts to break the soldered connection. Excessive vibration and/or physical shock could also cause these problems.

edit: Sorry, I didn't notice your comment about already re-seating the motherboard connector until after I posted this...

[ilyes]

Alright, thanks rkawakami!

Indeed, I already reseated the LCD connector to the main board with no success so far. I think I'm going to do the same for the second connector in the LCD panel. I applied some pressure at the bottom of the panel with no changes as far as the displayed pattern of those mysterious lines is concerned. I don't think that the GPU (or some other part of the main board) is damaged. I tried all the possible video resolutions, changed the device drivers, etc. but the symptom remains. I connected my laptop to an external monitor and it worked properly. I also did a capture of the content of the screen and it didn't show any distortion whatsoever (i.e no video memory corruption).

Currently I'm investigating the stuck pixel way (although it doesn't seem to be the case since I'm getting a whole block of pixels) by applying the "pixel massage technique". But I'm feeling like it's an issue with the panel's LCD driver...

The funny part of it, is that the block of malfunctioning pixels changes as I move the mouse cursor or some applications' windows.

Thanks for the support!

Best regards,
Ilyes Gouta.

[tfflivemb2]

I agree with Ray...check your LCD cable. I have seen them work themselves loose on the back of the LCD. The other thing is to look VERY closely at the LCD cable and make sure that there isn't any damage to the cable itself, especially at the seam between the LCD and the base of the T30, where the cable gets the most tension.

[ilyes]

Hi!

Thanks everybody for your input! It's really great!

This morning, I made my way through the LCD assembly parts and I was able to see the LCD's back connector. However, it was kind of protected by some white patch and somehow looked very fragile to manipulate so that I just backed off... It looked alright and solid/properly attached tough.

Back to the LCD cable, I remember it looked like just a little bit twisted/bended near the white cables (see the pictures) due to the tight assembly. However I don't think that such deformation is the cause of my issue.






Thanks guys for the support! Any suggestion is more than welcome.

Best regards,
Ilyes Gouta.

[phool@round]

I'd replace the cable and if that doesn't clear the issue the screen will have to be next because the control board is not a replaceable item and the manufacturer uses exotic equipment that most of us don't have handy in our asenal of hand tools. I wish I had an infra-red or ultra-sound soldering machine........

*To remove the upper lcd connector under the white tape:

Do not touch the upper edge when looking at the back, you'll break the very very fine traces or wires under the brown transparent lcd control connections. Usually the control board goes down one side as well but I can't tell from the pictures what side, just be careful and hold the screen gently from the sides, maybe with a flat hand on the edge. Unscrew the mainboard connector then unscrew the lcd panel from the hinges on the base but leave them on the lcd screen. If you need to hold the lcd hold it by the bottom edge. Lay it face down on a table with the bottom resting against your body. I use an exacto knife to *gently* gather enough tape on the upper connector to get a finger hold on. Pull the tape slowly towards you about 180 degrees until the connector comes out. It's easier than it looks. Just take your time, be patient and don't use alot of force.

Or if you have the funds you can buy a whole unit and just unscrew the screen.

I'm pretty sure it's the screen by looking at the pictures but having a new video cable isn't a bad thing to have when replacing an lcd. You'll be starting with a fresh repair that way.

[ilyes]

Hey,

Thanks for the answer and the instructions! I almost tried out/checked every possible cause and I agree with your diagnostic (a cable issue or the LCD panel that has to be replaced). The problem is that my laptop isn't under warranty anymore and that I can't really have hardware parts replaced (can't even make an order): IBM (or Lenovo) isn't represented to serve customers directly here in Tunisia, only companies (and there is only *one* representative to cover all the country!)... duh.. I can go with out local techies however I'm pretty sure that they're going to diagnose the issue and then block there (no h/w replacement parts available). So I guess I'm going just to live with it...

Anyway, thank you guys for your great support! I really appreciate!

Best regards,
Ilyes Gouta.