Help with iMac repair

2015 iMac was working fine until I tried to erase and reboot for sale.

Now I can’t get past the disk utility phase so I’m looking for someone to check it out and see if any hope for repair. Any ideas?

Provided you have a wired keyboard, try restarting holding down the Command key (to left of space bar) and the R key. Keep holding until you see a list of options.

You need to be connected to the internet (wifi or Ethernet cable).

One should be 'restore Mac OS'. This will take at least 3 - 4 hours.

If this does not work you can call me on 07973 269654 (East Dulwich).

Thanks so much for this!

It’s worked - apparently a common problem.