Laptop screen unreadable but works OK if being twisted

[Peroxyde]

Hi,

It's looks like like my week of laptop troubles. It's a HP Compaq nc8430. A month or two ago, the screen had shown some horizontal and vertical lines sporadically and then worked OK after a few reboot or waiting for a few minutes.

Now the screen is unreadable, either plenty of random lines or it just looks like a dirty gray paper with random black smears, especially around the border.

If I hold the two top corner of the screen and twist them about 1/2 an inch. Then the display comes back normally. Looks crisp as before. Releasing the twist and the screen content is slowly filled with a gray starting from the border to the center. Re-twist the corner and the issue disappear again.

I guess there is an electrical contact issue somewhere. Trying to pinch around the plastic border or pulling on the hinge didn't help anything. Only twisting the corners would make the screen display come back.

Is it serious? Is there anything simple that I can fix?

Thanks in advance for any help.

 

[BTA]

If you're lucky it's just a ribbon cable that needs replacing.

If not, you're gonna need to replace the screen.

It's generally not that hard to do, just get a small set of screw drivers and keep track of the tiny ass screws.

 

[Peroxyde]

If you're lucky it's just a ribbon cable that needs replacing.

If not, you're gonna need to replace the screen.

It's generally not that hard to do, just get a small set of screw drivers and keep track of the tiny ass screws.

I have dis-assembled just enough to expose the ribbon and separate the LCD panel from the bevel casing. Touching, moving the ribbon or connectors didn't have any effects on the screen (still remains unreadable).

Only when the top border of the panel is bent that the display come back to normal. I've got a few hits on Internet searches talking about laptop panel issue. It seems that "failure of the ribbon cable to glass bond is a common problem". May be this is what I got. I have no idea how to replace the ribbon and how to redo the bonding.

I am afraid I need to look for a used panel or buy a new laptop.

Thanks for your help.

 

[BTA]

It's been a while since I've really had to work on laptops but...

Open up the top of the case around the screen.

Take a look behind the top of the panel and see what is there, sometimes there's a PCB board, or sometimes just ribbon cables. Now turn it on and see what happens to the screen when you put pressure along different parts of the back of the top of the panel with your fingers. You're basically just trying to narrow down the trouble spot. Check all connections of any PCB's that might be behind or around the sides of the panel as well.

I used to have some luck a long time ago by placing a sheet of thin foam (usually the pink sheets that used to come with new motherboards) behind the trouble spots. It made it hard to put the case back together but sometimes it would apply enough pressure to fix the problem. Not really a permanent fix though.

I think you're looking at a new screen at the end of things though. Sometimes you can find cheap replacements on ebay, just find the part no off the panel.

 

[Peroxyde]

Hi BTA,

Thanks for the advice. I did exactly what you suggested. Applying a pressure point around the back of the panel, using my finger and then the handle of a tooth brush. No effects!

The only way to restore the display is to bend the top edge of the panel. I've tried to narrow down the trouble spot by pinching various spots on the top panel but nothing worked. Only bending the edge had an effect.

 

[corkyg]

Sounds to me like the thin film applied to the glass matrix is defective. That means screen replacement.