Blank screen, LED power light on

Hi there, I have a Dell S2716DG and the screen has stopped working, although the LED power light remains on when connected. It is normally connected via a DP to USB-C cable to a MacBook Pro (‘16). I have tried the method on Dell support forums of removing cables and holding buttons down etc but no success.

Other notes;

- We had a short power cut since I last used it

- I’ve tried various other cable combinations

- An old MacBook Pro seems to recognise/detect the monitor via a HDMI to HDMI cable but the monitor screen stays blank. The newer MacBook doesn’t detect it at all.