I’d suggest you call Sonos Support directly to discuss it.

When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.

Tried that twice already.  They were no help.  Wanted me to send back to them and give me a coupon to buy a new one.  I’m thinking they would fix it and resell it refurbished.

LOL the Play:3 is way too ancient to be re-sold as a refurb.

So I’m guessing it just stops playing for no reason because it’s way too ancient?!?!

I have a pair of PLAY:3s that are working fine, so there is no generic ‘they all stopped working’ thing out there. There is a small computer inside of every Sonos device, it is possible that some part of the electronics inside it have failed, for some reason. Without Sonos support looking at that possibility, there isn’t much we can do here in the community. 

My Play 3s, about 15 years old, are still working fine too.

I’d suspect an internal fault, rarely user repairable, and take the upgrade offer. You might be happy with one of the new Ear 100s as a replacement.