Interesting challenge with DELL Latitude 7400 and DELL Latitude 7430

[Stefan Steff]

I have 3 DELL Latitude 7430 with faulty MBs and 2 DELL Latitude 7400 with broken screens.
Both have 14'' touchscreen with 30 pin eDP
I try to connect the 7430 screen to 7400 and getting picture OK. Yuppie!
So far so good...
Reboot in BIOS settings to check battery, processor type , etc. everything is OK even the touch is working.
At this point I know everything is fine with pin assignment.
I installed a Windows 10 Pro x64 and as a big surprise the touchscreen is not working!
There is no mention about touchscreen in Device Manager… no device with yellow exclamation sign like touchscreen it not existing!
...so, Windows is not aware that it has a touchscreen in the hardware...
I suppose there is a solution to alter the 7400 BIOS to recognize the 7430 touchscreen but I don't have the knowledge to do it…
If anybody knows how to solve this problem please share his idea.
Thanks!
S.S.

[Wojtek_P]

I have similiar issue with Dell precision 7540. I swapped non-touch screen to touch screen from 7530(as they are same),touch screen does not work and Windows does not see touchscreen device.