LCD green haywire

[zak3000]

Hi folks

I have read almost 8 pages of LCD issues in this forum, and could not find a match for my horror story. So, here it is:
I have a T43-2686DGU computer. As unlikely as it might sound, the CPU went kaput lately. So, I replaced it with an identical one. After assembling the latop, I powered up and things were fine, but for a little while. 15 minutes down the road, I started seeing a light bright green haywire of flickering pixels running vertically along the center of the screen. I freaked! The green flickering pixels started appearing all around the LCD, until the image is totally distorted.
I thought it was the mobo 42t0073, but i replaced it with a NEW [another story that is still unfolding] one and had the same issue again. I returned the mobo to the seller who proved that the board was fine.
NOTE THAT I expedited the process of getting more green pixels by running NFS carbon. Green pixels were all over the LCD in less than 15sec into the game intro video.
I suspected GPU overheating, but i ran tpfancontrol and found normal readings.

From my reading in this forum, it seems the next suspect is the Inverter, but I need this forum's Guru insight to the problem.

Please help. thanks.

[Harryc]

Swap the LCD cable then the LCD itself, in that order. An entire LCD assembly with cable, inverter, and LCD would do nicely.

[zak3000]

thanks Harry

Unfortunately, I don't have this luxury since i don't have spare parts.

Any other ideas of what the culprit would be?

[RealBlackStuff]

What do you see when you hook it up to an external monitor?

[zak3000]

the external monitor works fine.

Oh! I forgot to mention: These symptoms do not appear when the laptop is cold, that is, immediately after booting. So, I have to cool it down considerably before i reboot. But, like i said earlier, the tpfancontrol reading are all below 70, all time as long as i don't play games.

Also, do you think the CPU got busted because of whatever is failing the LCD?

[ajkula66]

I'd suspect GPU failure, more precisely VRAM corruption.

Let's hope I'm wrong because if I'm not you'll need a new motherboard.

Run PC Doctor for DOS on all system components, including the LCD, several times and report back.

You can scratch the inverter off your list of suspects, BTW.

Good luck.

[zak3000]

PC doctor was the first thing I ran after seeing these symptoms. I have done that 9 days ago.
Now, the laptop is taken apart.

There has been no unusual report from PC doctor. The only thing i have there is the LCD green pixels, getting more numorous as the laptop runs longer or on graphics demanding application.

As to VRAM corruption, I would be utterly disappointed since the mobo is NEW, and has been tested on another laptop with no such issues.

Frustrating, indeed!!!!!!

[poshgeordie]

I would second it being something to do with the graphics chip.

These symptoms are similar to a problem with Apple Macbook Pro's fitted with the ATI chip, which do exactly the same thing if the chip temperature rises above 55c.

Having said that, Thinkpad graphics chips are not generally affected by high running temperatures in this way (ignoring the solder ball issue), so to be sure I'd want to try it with another screen before blaming it on the chip.

<EDIT> Just re-read your original post and you say this is the second motherboard showing this fault. This is such an unusual problem that I would say it's NOT the graphics chip but something else.
I'm leaning towards a screen problem....

[poshgeordie]

Some questions:

This is on your T43 with the ATI X300 graphics chip?

If so, do you have a long heatsink which covers both the CPU and the graphics chip.

If this heatsink is fitted, is there a pink coloured pad between the heatsink and the top of the graphics chip?

Does it fit firmly on top of the heatsink and does the heatsink get warm above the graphics chip?

When you fitted the CPU did you renew the heatsink compound? (This is a general question not necessarily related to your problem) If you didn't you should, but apply a very thin amount on the metal part of the CPU.

[zak3000]

TO poshgeordie:
I confirm all your questions:

1- Long M22 Fan leading to the ATI X300 graphics chip
2-The pad does exist. Like I mentioned earlier, i doubt to be a heat problem since tpfancontrol readings are all normal below 70
3- I did apply MX-2 heat paste to the CPU.

[poshgeordie]

Mmm I think it may be a screen problem.

[zak3000]

In my mind, I am certain it is a screen problem. But, what exactly it? inverter? LCD? cables? bulb???
That is what I am looking for.

[Harryc]

No way to isolate it without parts. Like I said earlier, "Swap the LCD cable then the LCD itself, in that order. An entire LCD assembly with cable, inverter, and LCD would do nicely." I really doubt this is an inverter issue.

[zak3000]

Thanks Harry.

In case i buy an LCD cable, is it easy to swap it safely? I am a technical person, and I have some basic tools like an analogue multimeter and screwdrivers I don't have soldering tools at all.

[poshgeordie]

This strip down / rebuild document should help you.

The only tools you need is small crosshead screwdriver.

[zak3000]

poshgeordie:

The link you provided points to an enhanced version of the HMM. I am actually looking for guidance towards dealing with the LCD cable swap process, and how difficult it might be.

thanks for the help.

[Harryc]

Use this maintenance manual -
http://www-307.ibm.com/pc/support/site. ... 58791.html

[zak3000]

man! I was reading the manual like a blind bat!! I will check and see what I find in the panel. It will be a while before I can do that, may be over the weekend.

thanks guys for the help. I will keep you posted.

[ajkula66]

If you really want to play, and not spend too much money...

I have a complete spare lid from a 14" T43p. The LCD itself is damaged, but it DOES display and with correct colours.

If you install it, and the green monster comes back, kiss your planar goodbye.

If the broken screen displays clean within its abilities, just buy a replacement LCD.

[zak3000]

ajkukla:

Thanks a lot for the offer. It is really about my tight budget these days

Correct me if i am wrong: Being a spare lid means it is lying somewhere in your house, and not connected to a board, therefore, you may not be able to provide me with a photo of how it looks like when operational. Right?
If otherwise, PM me with a link to a picture.

thanks again guys....

[ajkula66]

If you can wait a couple of days, I can hook it up to a board and email you pictures...

Just realized you're in Canada...may be more trouble than it's worth just because of shipping cost...

Will keep you posted...

[zak3000]

I can wait for you. I am actually waiting to resolve a claim on ebay that shall release funds for buying a T43p mobo. I have a quote now, but still higher than expected, for a 4 years old mobo . In fact, if i am able to pay slightly more, i can definitely buy a brand NEW Acer Netbook.

[ajkula66]

zak3000 wrote:

In fact, if i am able to pay slightly more, i can definitely buy a brand NEW Acer Netbook.

Please don't...

[zak3000]

I am still waiting for the LCD photos.

[ajkula66]

Sorry, been extremely busy and still am...