Cistern advice before I call a plumber

[Ekphrasis]

Vaguely hopeful anyone can help before I call a plumber...

It’s stopped filling up; dh thinks a deal has gone and spent some time on YouTube but couldn’t work anything out. Any ideas? I fear an expensive flush!

Have you tried to manually move the ball cock?

Yes I think that’s what dh tried yesterday with a screw driver

It could be that the cock is stuck up, push it down and see if it starts filling up

Yes we were doing that and I was working. Not working now - I’m thinking it’s a plumber job