IBM Thinkpad display problem

[OCEANRADIO]

The LCD is extremely dim, almost unreadable. The external display works fine.
When power is removed from the inverter and replaced the display comes on
momentarily at normal brightness. Likewise when the lid switch is toggled, the
display lights up for about one second and then dims. It is barely readable
when dim.
I replaced the inverter and that didn't change a thing.
got any ideas?
John

 

[George Macdonald]

The LCD is extremely dim, almost unreadable. The external display works fine.
When power is removed from the inverter and replaced the display comes on
momentarily at normal brightness. Likewise when the lid switch is toggled, the
display lights up for about one second and then dims. It is barely readable
when dim.
I replaced the inverter and that didn't change a thing.
got any ideas?

We have an A22m PIII/800 in the office which acts similarly though it's
still readable when it dims. If I twist the lid just a touch, by holding
the left side and pulling forward on the right side, it lights up to normal
brightness and when released fades back again - I've been told by the
former user that it also occasionally goes completely black.

The twist thing tells me it's something in the lid/display itself which has
gone awry, probably due to physical shock or bending. Since you mention
inverter, I assume you've downloaded the hardware service manual:
http://www-3.ibm.com/pc/support/site.wss/MIGR-39298.html ? I haven't
bothered to investigate further yet because I have my doubts about taking
the lid/display apart... and the machine is now little used. Have you
asked over at http://forum.thinkpads.com/ ? Apparently there are "upper
half" pieces of Thinkpads on sale at Ebay which might be the easiest
solution.

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??

 

[OCEANRADIO]

George:
thanks for your helpful reply. I had not checked that forum but have since and
there is a wealth of information along the lines of my problem.
I have taken the laptop apart a couple of times and it kind of sounds to me as
if the ribbon cable of your laptop may be the culprit. A technician told me
that these often fail from use, i.e. raising and lowering the lid. And as
cheap as they look, they aren't. I couldn't see how that could be the problem
in my case as I flexed the cable and it makes no difference.
I tried flexing my lid as you described but it didn't change anything.
I'm still working on it and am slow to send off $90 or so for a used LCD, but
if it comes to that, I will. I was so sure it was the inverter!
This 600X was sold as reconditioned about two years ago and lasted about one
year before this failure. It happened while I was using it and it wasn't
dropped at the time. I failed during power up. Since it's my wife's laptop
it's my job to fix it. This is on the top of the stack of things to fix. Just
below is the IBM 390E that failed and caused my wife to buy the 600X. The
problem there is said to be the system board and a replacement is on the way.
Here's hoping that's it.
Best regards,
John

 

[George Macdonald]

George:
thanks for your helpful reply. I had not checked that forum but have since and
there is a wealth of information along the lines of my problem.
I have taken the laptop apart a couple of times and it kind of sounds to me as
if the ribbon cable of your laptop may be the culprit. A technician told me
that these often fail from use, i.e. raising and lowering the lid.

Yes, I suspected the ribbon cable at first but, without taking the lid
apart, just poking the cable, with a blunt object, and raising/lowering
the lid doesn't affect the dimming syndrome - it needs the lid twist so I
suspect it's more likely the inverter or backlight tube. This system has
done a lot of travel and has been taken home every day - seems to be a bit
of a latter day status symbol that.

And as
cheap as they look, they aren't. I couldn't see how that could be the problem
in my case as I flexed the cable and it makes no difference.
I tried flexing my lid as you described but it didn't change anything.
I'm still working on it and am slow to send off $90 or so for a used LCD, but
if it comes to that, I will. I was so sure it was the inverter!

From what I gathered from a brief scout around the above site, the inverter
was a good bet but if it's not that, and there's no weird color offsets or
other obvious LCD artifacts, it's most likely the backlight tube. I also
gather the backlight is not available as a replaceable unit(?), though
someone claimed to have swapped one between two lids with some delicate
"surgery". I guess it boils down to an "upper half" replacement.

This 600X was sold as reconditioned about two years ago and lasted about one
year before this failure. It happened while I was using it and it wasn't
dropped at the time. I failed during power up. Since it's my wife's laptop
it's my job to fix it. This is on the top of the stack of things to fix. Just
below is the IBM 390E that failed and caused my wife to buy the 600X. The
problem there is said to be the system board and a replacement is on the way.
Here's hoping that's it.

Good luck with it all.

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??

 

[longhairlaw]

I rather think it is a resource issue. I recently reinstalled my Win98
se and upon changing settings for the ethernet card, the display
flickered and went dim. I've tried to reset it without success. It
used to be bio and now is pci. It used to be in the system with the
monitor now it is with the usb and the ethernet card. I have it on 15
and there is a share but no conflicts other than no brightness to the
screen. I'm not a techie, and would like to know if anyone resolved
this issue. I can't buy another computer right now. And this one
serves my purposes just fine at home. Thank you.

 

[philgoetz]

I have a similar problem. It's not a hardware problem. It started when I accidentally pushed one of those stupid Thinkpad key sequences that messes with your hardware. I don't know what the key sequence was, but it made my display change to a small window, maybe 800x600, in the middle of the screen, with the rest black. I tried to fix it by pressing fn-F7 (display settings) and choosing "normal settings". This made the screen go blank. I left it alone for an hour, and when I came back, the screen was normal.

I thought all was well, but the next time I turned the computer off and on, it came up again in the 800x600 mode. I pressed fn-F7 again, and chose normal mode, and the screen went blank. The computer was still working; I could type and get beeps in response. I gave up waiting for it to change back itself, and turned the computer off and on. Ever since, I've had the dimness problem. It will flash bright not if I press the lid button, but if I press fn-F7, for a fraction of a second. It's not an OS problem, because it's dim on boot, even if I don't boot to Windows.