RE: external U2715H blanking after new video driver installed HDMI
The aupport assist indicates it is for my model . I didn't update for a long time as I know that updates can break a working system.
The current driver has other issues particularily with outlook and Oracle virtualbox which are just as annoying.
BUt I will have to go back and complaing to Dell. I have 3 years service on it so they'll send someone round to replace the Mainboard or the video board probably.