On Jul 6, 12:02*am, mike wrote:
On 7/5/2012 10:54 PM, Jeff Liebermann wrote:









On Thu, 5 Jul 2012 22:35:42 -0700 (PDT), spamtrap1888
*wrote:

So how can I tell if it is the display, the backlight, or the
inverter?
And could someone give me an idea what's involved in replacing each?

Clean the screen. *Fire up the laptop and get it to boot. *Darken the
room. *Use a flashlight at an angle to see if you can detect any text
on the screen. *For Windoze, you should see the Windoze logo as it
boots. *If you do see an image, your LCD panel is probably fine, and
you are having a problem with the LCD inverter or the CCFL lamps in
the panel.

It's also a good idea to plug an external monitor into the VGA port to
see if the video card is working.

Determining if it's the inverter or the CCFL lamp is a bit tricky. *If
you get a pink colored dim background, it's probably the CCFL lamps.
These are a major project to replace. *You'll find instructions on web
sites selling LCD panels and CCFL lamps.

The way to be sure is to open the display section and attach a test
CCFL lamp to the inverter.
http://www.insidemylaptop.com/remove-replace-lcd-screen-ibm-thinkpad-....
The LCD inverter is in the display section of the laptop. *You only
need to go to Step #9. *The hard part is splitting the LCD frame.
Don't use a metal screwdriver to pry open the display.

www.ebay.com/sch/i.html?_sacat=0&_nkw=thinkpad+t43+lcd+inverter
I usually buy two to avoid surprises. *Note that there are different
part numbers for different display types. *You'll probably have to get
the number off your inverter to be sure which is the correct number.

Bug me if stuck.

What do you mean by dimming? Dim? Dark? off?

Dim. Going but not gone.


Another way to check the inverter is to waive an oscilloscope
probe around the area of the inverter. *If it's running, you
can often see the radiation from it on the scope.


Most people don't have 'em, but an ultrasonic leak detector translates
ultrasonics down to the audible range. *You can easily hear the inverter
transformer "singing" and hear it change as you adjust the brightness
setting.

I'm interested in hearing how to check CCFL lamps.
In the old days, you could plug on just about any inverter and see if
it lights. *Today, the proliferation of connectors and inverter
topologies makes this harder.

I bought a fluorescent lamp checker at a garage sale.
It's basically a transmitter. *You waive the antenna around
the lamp and see if it lights.

I don't have that model, but I did have a thinkpad with a bad fuse.
Was located near the display connector and well disguised. *Didn't look
like a SMT fuse at all. *Was open and extinguished the backlight.

Backlight is still working somewhat. A lot of good tips, thanks.