EliteBook 840 G4 - How to get USB C to DisplayPort working

[daveblohm]

I contacted HP to find out if DisplayPort was supported over USB-C. They told me it was. I went and bought a USB C to DP cable, hooked it up and it's not working. 

Is it not supported? Is there a setting I have to change? Any advice is appreciated.

[banhien]

@daveblohm

Machine has the following ports (from its manual)

VGA (Dsub 15 pin) supporting 1920 x 1200 external resolution @ 60Hz; hot plug/unplug and auto detect
USB 3.1 Gen 1 charging port
USB 3.1 Gen 1 port
USB Type-C (basic)
DisplayPort
RJ-45
Docking connector
Audio-out (headphone)/audio-in (microphone) combo jack

Now, what is the meaning of basic I can't find an answer but it should work. By the way, it has DisplayPort why you need USB-C basic ?

Regards.

[daveblohm]

I'm using the DisplayPort port for one 4k monitor. HP support said I could connect a second 4k monitor via the USB-C port.

[banhien]

@daveblohm

EliteBook 840 G4 series has many configurations/options. Do you know what is the video card on your machine ? Doe it support TWO 4K monitors at the same time.

I believe it only has Intel® HD Graphics 620 which supports   4096x2160 @ 60Hz max.

In short, you can't use two 4K monitors on your machine.

Regards.

[JustinV2]

Do you know what, if any video it supports over USB-C? 

And/or if theres a limit to the resolution or standartd that it will support in a dock over USB-A 3.1 ?

My EliteBook 840 G4 will work with a USB-A to USB-A 3.0  dock at work,  but will I'm trying to connect it to higher res monitors at home and the dock I have is a USB-C connection (which supports up to 2x 4K displays via DP on the dock).  However,  when connected to the dock the 840 only detects the peripherals and throws an error that "dispay connection might be limited"  (and then the external monitor connected to the dock never shows up on the PC).

I have updated all the HP, graphics,  and displayport drivers that I could find and also tried connecting the 840 using a USB-A (PC  side) to USB-C (dock side) cable, but had the same result of periperhals only with no monitor.