Thinkpads Forum

The LCD on my old 755c now just comes up as a white screen when I start it. If I plug a external monitor in it works perfectly. Would I be correct in thinking the inverter has died?

Or should I be looking for an issue else where?

I dont believe that is an inverter problem... on laptops, the lcd relies on a lightsource to light up the screen... if the inverter was dead... you would not be able to see the images on the screen unless you were to shine a lightsource at the screen, then you could faintly see something.

If you have a totally white screen... the white is coming from the light source... so thus the inverter is working...

on a 760el I have... if i turn the backlight up too high, i see nothing but white... i'll get some pics up in a bit on the web...


EDIT: here are the images... (4 @ 256k total)

Brightness/Contrast adjusted as best as possible: http://conradshome.com/760el_backlight/normal.jpg
Brightness/Contrast adjusted all the way down: http://conradshome.com/760el_backlight/down.jpg
Brightness/Contrast adjusted all the way up: http://conradshome.com/760el_backlight/full.jpg

Here is a closer shot of all the way up... i can still barely make out the bios setup... but it is almost totally washed out: http://conradshome.com/760el_backlight/full_detail.jpg



http://conradshome.com/760el_backlight/full_detail.jpg

Thanks for your help.

Unfortunately it doesn't seem to make any different when I change contrast or bright settings on the side of the monitor. I tried playing around with the IBM hotkeys with no luck

I uploaded a photo of what it looks like.

http://www.picupine.com/7871220x

Yea, I'd say the backlight is DEFINATELY on... I am unfamiliar with how the sliders actually work... if they provide resistance... then it's possible there is a bad connection or one of the slide's contacts is bad.

On my 760EL there are 2 sliders on the screen... one is contrast and the other is brightness... even when i slide both all the way up and the screen is WHITE... there is still a ghost of an image very faintly if i look at an angle... like with the lid halfway closed.

I have the same problem, and when the white screen appears, I switch between the LCD monitor of my 755, to an external monitor using the keys combination to do it (even without an external monitor pluged in), and after two or three times, screen was working again. I can only associate this with a hardware problem, or maybe a driver issue. Hope it helps.

I have a 750 that was bought with exactly the same problem. Replaced the inverter and now it's great...

Often the cause of problem is a broken LCD cable, when there is a back light but no picture or the picture is corrupted.