Three speakers with hardware faults? Not where I am putting my money. My money is on a network problem. I suggest you submit a system diagnostic and either post the confirmation number here or call Sonos Support with it.
Or tell us more about your network, Sonos equipment and the nature of the problem.
If they truly won’t come on, as in you unplug them, wait 30 seconds and plug them back in and see no lights then it may be a hardware failure.
Calling Sonos support, no matter how aggravating is your best bet.
Sending a diagnostic and passing them the ID number can be a time saver if you can get to the point you can do that.
Moderator Edit: added link to Sonos Technical Support prior to marking as Best Answer.