Not a lot that the Sonos user community can do in this instance, except to say try a different power cable and/or fuse and power outlet, that’s if not tried already. If they are not powering on then it sounds like they have an hardware issue.
I was at my Sons house earlier and the Play:5 (gen:1) and Play:1 speakers there were working okay with the S1 App.
If no joy, and no sign of them powering on, then it maybe best to contact/chat with Sonos Support Staff via this LINK and see what the Staff can perhaps suggest to resolve the matter.