Thanks for the update. My Acer was the same. Had it looked at and was told it was probably the hard drive and a new one would be about £100. Told him I'd think about it. Like you said it's £100 towards a brand new laptop. At home I connected the charger again and gave the on switch a long press. I could feel life but a blank screen. Then suddenly a banner popped up if I wanted to do a factory reset press F something or other. So I did, nothing to loose.
I ended up having to redownload a lot. I mainly used that laptop for watching Sky Sports so I downloaded the App again and it worked perfectly.