RE: Dell TB15 Desktop Dock - Step-by-step driver/firmware/BIOS installation instructions for XPS, Latitude and Precision notebooks
On another thread user @Thysanoptera was suggesting that overheating might be the cause of the dock DisplayPort instability. He does have a point: the dock gets quite hot to the touch, it doesn't have an active cooling and the case has no venting whatsoever.
I quote him:
"The dock is overheating and I'm 100% sure it is the cause of at least the problems with Display Port going off. My display goes off after 1 to 3 hours. I opened the dock, put heat sinks on couple of chips (usb hub controller and DP hub) and that resulted in 12 hrs of trouble free operation, but the display still went off. So the next time I kept the case open and for 24 hours had no issues. Closed the case (partially) and display went off after an hour.So this time, without turning anything off, I just blew the air over the the dock motherboard - and the DP screen came back on.
Dell should recall this thing, it is going to be really funny when summer comes. I'll keep mine, just mod it with a fan, I'm pretty sure the new batch has the same design flaw and it is only a matter of time when every single customer will have issues. My dock was working fine for three weeks.
As far as DP monitor going off is concerned, I can replicate this at will, it's the DP hub - VMM3320, the Synaptics chip. The USB hub controller gets also hot as *** and is rated at 70C only, maybe that's responsible for the other stuff people report, Ethernet depends on it also. I'm pretty sure that just cutting some vents will be enough. I can't believe Dell just sealed the case completely without allowing any airflow."