I have a new Surface Pro 4 with a Surface Dock. I have connected my Dell S2340T monitor via the mini display port on the dock and the HDMI input on the monitor. I can see the screen fine but I get no touch features in Windows 10. Touch still works on the Surface's screen (I have it set for duplicate screens) but not on the monitor. Any ideas? It seems to be impossible to use Dell's online chat or telephone support as there is no service tag for the monitor!
The S2340T was only validated in Windows Vista/7/8/8.1. So we can only give you a guess as to how to get it working in non-validated Windows 10.
For touch to function on the monitor, the monitor USB upstream cable should be connected directly to the computer USB in port. I would remove the dock from the troubleshooting and test the monitor directly to the Surface Pro 4 =
Surface Pro 4 mDP out --> mDP to DP converter --> S2340T DP to DP cable --> S2340T DP in
Surface Pro 4 USB out --> S2340T USB to USB Upstream cable --> S2340T USB Upstream port
Many thanks. Actually, when I finally got my external hard disc connected (needed software) and found the user guide pdf, I had discovered this was my error. As I had used a Startech hub with special software to connect my Surface Pro 0 with the Dell monitor, using only one cable, I had forgotten it would normally need two. It now works fine except that I get a "glittery" interference on plain black screens. I have the screen set to 1920X1008 with refresh at 60hz. Any idea what is causing this?
1920x1080 60Hz is the prime resolution. Do you see the glittery interference when the monitor is not connected to any device and running the Built-in Diagnostics (page 43) ? If not, then the monitor itself is fine. So other hardware is the culprit.