Trouble with XPS 15 9550, USB-C/Thunderbolt 3, and external monitors
After the time spent with Dell Support doing diagnostics and updating video drivers to those official Dell drivers on the support page, my new XPS 15 9550 with 4K touch display continues to struggle when using external monitors. I have two (2) Dell U2515H monitors.
I have updated ALL of the drivers and BIOS to the very latest files available on the Dell support page, including the newest Thunderbolt 3 driver.
When the laptop is NOT connected to any external monitors, I am NOT experiencing any trouble.
When the laptop is connected to ONE external monitor via the onboard HDMI port, I am NOT experiencing any trouble.
Trouble begins with the addition of ANY external monitor via the USB-C/Thunderbolt 3 port.
I have experimented with the following three adapters, all producing the same result:
- Dell USB-C to HDMI (2.0), part number 047KD7
- Dell USB-C Port DA200, part number 5KMR3 REVA00
- Cable Matters USB-C to DisplayPort