Just to be clear on these points, changing the power option from "Do nothing" to "Sleep" on closing the lid resolved the problem of the blank screen on reopening the lid, necessitating a restart. I...

Yes, the screen is like a fridge light: you don't need it on when the door's closed. But on my machine if switching off the screen is all the lid does it forgets to switch it on again. Waking up from...

I'm in the UK and just got W10 CU. It all seemed fine on my old Acer laptop till I closed the lid: on reopening I got the blank screen. This was odd because I've always had "Do nothing" set in the...