X220 no display on DP-to-HDMI cable

[Thinkpad_user]

Hello ThinkPad lovers

I have an X220 Tablet with modified BIOS (v1.46).
Dual monitor was working without issues using a DP-to-HDMI cable but suddendley stopped.
I tried using different cables, different TV's, laptop DP port and UltraBase DP port but without success.

I don't know if this has any relation, but i was messing in BIOS advanced options trying to setup an external GPU Dock.
VGA dual monitor works fine.

Any help or suggestions will be appreciated.

Thanks in advance.

[dr_st]

Welcome to the forum.

Sorry to hear about your trouble.

Since you tried changing most of the hardware that can be changed, and the result is the same - did you consider a software issue?

Try reinstalling the GPU driver / booting a different operating system through LiveCD.

[Thinkpad_user]

Thank you dr_st, sorry i was away.

For software side, i tried :
4 different windows 7 systems including two fresh installations (with generic drivers).
3 different ubuntu installed systems, and many many live systems (USB and ISO's).
Not solved yet.
The same systems worked before.

I think it's related to advanced BIOS options, if anyone had the same issue, any suggestion will be appreciated.
Thank

[dr_st]

I don't have experience with the modded BIOS, but if there is an option to reset all BIOS settings to default, I would try that (unless you already have).