Thinkpads Forum

I was trying to get my t420 to use the Nvidia 4200m graphics in liunx so i went into the BIOS and changed the display to Discrete. Now it boots to a black screen. The back light turns of for a few seconds then goes out. It appears to be booting normally and i was able to navigate the BIOS blind to switched it back integrated. I tried to update my bios. Its now on bios version 1.52 and still has the same problem. I have a 1080p screen installed. Could that be causing the problem? Or is my Nvidia chip dead?

Can someone confirm wether or not the discrete graphicss setting in bios works with the 1080p screen upgrade?

Check the "stickies" at the top of this forum page for the FHD upgrade kits.

I have. There is no mention of anyone attempting to change to discrete in bios. I'm just going to have to assume my Nvidia chip is dead and order a new motherboard.

I'm just going to have to assume my Nvidia chip is dead and order a new motherboard.

In doing some troubleshooting, I also had that black screen happen. This on my T520. I also had nvidia disappear altogether from Device Manager. I have Win7, so not the same as Linux, but all I did, was turn power off. Then restart computer into BIOS and switch back to another Display setting. Finally got back to working system with Nvidia and Intel showing in device manager.

How did you navigate blindly within the BIOS? I have the same issue, but can't find my way through the BIOS nor a guide online.

Did you try connecting an external monitor?