Vertical lines on laptop LCD display
 

Hello everyone,

I have a dell inspiron 8100 laptop, with a 15 in. active matrix TFT
display ("UXGA" or ultra xga, capable of 1600x1200 resolution). About
6 months ago, the Sharp LCD on this laptop started displaying a
vertical blue line (single pixel width) about an inch and a half from
the right edge of the screen. Since the laptop was no longer under
warranty, I did a little web research, and discovered that the "flex
cable", which presumably carries the data bus, reset lines and so on
(there's a separate power cable), had a tendency to malfunction, since
it had a 90 degree "twist". Unfortunately, reseating this cable, and
replacing it did not help. However, I did discover that applying
pressure to one of the dark plastic (it almost looks like film) areas
on top of the lcd, near the always-on line of pixel, tended to fix the
problem. These film-like plastic sheaths seem to be adhered to PCBs on
the rear of the LCD, but they seem to be non-conducting, and I'm
unclear as to what their purpose is - there is an elliptical metallic
area at the centre, and there are sever. They're labeled STAB0, STAB1
(through stab 12 or so - there are horizontal versions as well,
leading me to believe that they're associated with the row/column
control lines for the TFTs) and so on. I cannot find a schematic for
this LCD on the web, unfortunately. I've used LCDs with attached
controllers (the HD44780 for instance) for microcontroller projects,
but those tended to be relatively simple, with an 8 bit data bus and a
few other lines such as register select, r/w and so on, so I'm rather
lost when it comes to this sort of display :-) Since the problem first
appeared, it has worsened, and there are now 10-12 lines which are
"always on". I don't believe the actual transistors are dead, or that
there's a problem with the display itself, but it seems to be a loose
contact of some sort. Any thoughts or anecdotes of how this sort of
problem can be fixed would be appreciated!

Vertical lines on laptop LCD display
 

(Derek) wrote in message . com...
Hello everyone,

I have a dell inspiron 8100 laptop, with a 15 in. active matrix TFT
display ("UXGA" or ultra xga, capable of 1600x1200 resolution). About

snip

I'm afraid that this means the display driver chip for that area is
fried . The good news is that sometimes they can be repaired . Try
www.man-machine.com

If it is FUBAR then they may be able to find a replacement display for
you, for less than a new one would cost .

-A

Vertical lines on laptop LCD display
 

(Derek) wrote in message . com...
Hello everyone,

I have a dell inspiron 8100 laptop, with a 15 in. active matrix TFT
display ("UXGA" or ultra xga, capable of 1600x1200 resolution). About

snip

I'm afraid that this means the display driver chip for that area is
fried . The good news is that sometimes they can be repaired . Try
www.man-machine.com

If it is FUBAR then they may be able to find a replacement display for
you, for less than a new one would cost .

-A

Vertical lines on laptop LCD display
 

(Andre) wrote in message . com...
(Derek) wrote in message . com...
Hello everyone,

I have a dell inspiron 8100 laptop, with a 15 in. active matrix TFT
display ("UXGA" or ultra xga, capable of 1600x1200 resolution). About

snip

I'm afraid that this means the display driver chip for that area is
fried . The good news is that sometimes they can be repaired . Try
www.man-machine.com

If it is FUBAR then they may be able to find a replacement display for
you, for less than a new one would cost .

-A
I can buy a replacement LCD on ebay for ~$150, and I'll do that if I
can't fix the problem. I suspected the control logic for the display
as well, but given that pressing down on various areas of the control
lines fixes the problem, I don't see how replacing the chip would
resolve the issue - seems more like a wiring issue from my
perspective. Thanks for the response :-)

Vertical lines on laptop LCD display
 

(Andre) wrote in message . com...
(Derek) wrote in message . com...
Hello everyone,

I have a dell inspiron 8100 laptop, with a 15 in. active matrix TFT
display ("UXGA" or ultra xga, capable of 1600x1200 resolution). About

snip

I'm afraid that this means the display driver chip for that area is
fried . The good news is that sometimes they can be repaired . Try
www.man-machine.com

If it is FUBAR then they may be able to find a replacement display for
you, for less than a new one would cost .

-A
I can buy a replacement LCD on ebay for ~$150, and I'll do that if I
can't fix the problem. I suspected the control logic for the display
as well, but given that pressing down on various areas of the control
lines fixes the problem, I don't see how replacing the chip would
resolve the issue - seems more like a wiring issue from my
perspective. Thanks for the response :-)

Vertical lines on laptop LCD display
 

Derek wrote:
However, I did discover that applying
pressure to one of the dark plastic (it almost looks like film) areas
on top of the lcd, near the always-on line of pixel, tended to fix the
problem.


It sounds like you're describing the flex cables that connect the glass
LCD panel to the driver board. I've seen a lot of these crack, or start
to make bad contact at one end causing single rows of pixels to stay
on. When you press on it, it temporarily restores the connection.
There's no way to repair this type of problem yourself, but I believe
there are companies that do repair this type of LCD problem. I'm not
sure if it would be cheaper than an LCD from ebay.

--
Andy Cuffe

Vertical lines on laptop LCD display
 

Derek wrote:
However, I did discover that applying
pressure to one of the dark plastic (it almost looks like film) areas
on top of the lcd, near the always-on line of pixel, tended to fix the
problem.


It sounds like you're describing the flex cables that connect the glass
LCD panel to the driver board. I've seen a lot of these crack, or start
to make bad contact at one end causing single rows of pixels to stay
on. When you press on it, it temporarily restores the connection.
There's no way to repair this type of problem yourself, but I believe
there are companies that do repair this type of LCD problem. I'm not
sure if it would be cheaper than an LCD from ebay.

--
Andy Cuffe