Thinkpads Forum

Hell you guys.

I have replaced the panel of my T420 to a 1600x900 panel, which is a great improvement but..

Im having some issues with brightness, cant use the keys to control brightness, and the screen dims down occasionally. Things are not working properly.

Searching the web, tells me im not the only one, and Lenovo is picky with the panels.

This is the panel iv'e used https://www.psaparts.co.uk/pno/scr0037b.html

and this is the cable https://www.aliexpress.com/item/3283016 ... 4c4dUcOaLK

Iv'e spent hours searching for a solution, but cant really figure it out. Should i replace the panel? The cable?

Ive seen these panels mentioned as working with the T420, LP140WD2. https://www.panelook.com/modelsearch.ph ... d=lp140wd2

Ive found a LP140WD2 (TL) (B1) panel for sale. Would that be the solution of my problem? I really dont want to go back to lower resolution.

Thank you.

Hi there,

sorry no experience here.. but generally speaking..

- this seems like a LED back-light panel does it not?
- was your previous panel LED or CCFL?

at least on T60 there is a separate "inverter" board hidden inside the screen. What is the situation on T420?

T420 is just LED, so don't worry LED vs CCFL.

Where are you testing brightness control? I believe T420's is controlled by software questionably enough so you can't adjust brightness outside an OS with the drivers installed.

atagunov




TPFanatic

Its in Windows 7. I updaed the drivers after installing this new panel. The controls seem to work, kind of. Sometimes, but only sometimes, i can dim the brightness down to 9/15, but when going to 8/15 in turns almost all black. Then i can duplicate my screen (using fn+F7), like if im using an external screen, the brightness goes up, and then switching back to computer only, and im back to "normal".

This is all with the power plugged in, with battery only its even worse..