Surface pro 4 won't turn on, how screwed is it?

I have a surface pro 4 that, until yesterday, had been working fine.

Went to switch it on yesterday though, and I got nothing.

So far I've tried the volume up + power long hold, power only long hold, removing charger both ends and retrying, other power points, and cleaning the ports.

Still won't switch on.

Charging cable light will turn off though during long holds, and come back on when I touch the power button again, not sure if that's expected or not.

Anything else I can try? Or am I looking at data recovery and a new laptop?

Thanks everyone!