I have a new Ultrasharp 29, and I cannot connect it to the Thunderbolt minidisplay port on the laptop. I also use a WD15 docking station, and the DP, used the DP cable which camw with the monitor, but no signal. HDMI works, DVI to a Apple DVI<-> HDMI works to Dell 5510, HDMI into WD15 docking station works. HDMI to Mac mini works (not DP to Thunderbolt).
Any idea how to get DP working from Monitor to Dell 5510? Maybe a bad cable? 5510 should be able to drive full resolution on monitor through the DP.
Did you ever resolve this? Are you referring to the 2012 U2913WM? The Precision 5510 has the newer USB-Type C/Thunderbolt 3 port. I have doubts that our older mDP to DP cable will work. You should get this dedicated USB-Type C/Thunderbolt 3 to DP cable.
I have not resolved this (holiday travel), and will give it a shot. If that is not it then the DP cable or the port on the monitor is bad.
The cable works, have not checked the resolution yet. It does not work for the docking station, this uses a DP port, and the laptop uses a Thunderbolt 3 port. So, this cable does not plug into the docking station. I will check the specs on the docking station again.