HP EliteBook 850 G8

[luca_m]

Hello,

I have had a rather strange problem for about a couple of weeks since I updated the notebook to bios firmware v1.20. Basically the USB-C ports work (charge the battery, read pen drives, etc.) but do not transmit any video signal to external monitors. I noticed that from the device manager in the USB controller detail the ports are not seen as thunderbolt or USB4. Into the bios the all the thunderbolt voices are enabled.

Has anyone had a similar problem and knows how to solve it?

I tried to restore the bios to the previous version but it does not allow me and gives me an error on an intel component while the flash is happening..

thanks 🙂

[resistencia]

Hi @luca_m 

try to make a power reset following the steps in the link below

HP PCs - How to power reset your computer | HP® Support

[luca_m]

Hi @Resistencia,

i already did it and not fix anything..

I also try to revert the bios to 1.19 but when it start to flash it gave me that error:

Update of the Intel Management Engine Firmware failed, because the target Intel Management Engine firmware update was found to be invalid.

and the notebook restart and mantain bios release 1.20..

[resistencia]

you should check in the BIOS that you have enabled the ability to revert to previous BIOS versions.

[luca_m]

i check the option and it was already selected the ability to rollback the bios..

[resistencia]

Are you sure, in Main in the menu there is no Update System BIOS option.

[luca_m]

I can start the flash of previous bios but when come the 2 component that is Intel Management Engine it failed with the error that i wrote yesterday..if i flash the latest bios release v1.20 it complete with success and no error.

[resistencia]

Unfortunately a BIOS rollback does not always work, and in particular I suggest you not to insist, it can damage forever the laptop if you can recover more of its functions.

[luca_m]

yes i know..the strange behaviour is that the usb-c ports work for all except video output...when i connect the adapter the monitor turn on but show the message going to sleep..

i think is a hardware malfunction but it start from the new bios release..

[resistencia]

I have only seen this error solved with the first answer I gave you'.  Otherwise you have to wait for another update.