What what is the source of your music? Are you Grouping any rooms? Are any of the players wired to your TP-link or the Network Switch?

Music source: Sonos Approved RadioApp & Spotify. No grouping and all players are wireless. 

Submit a diagnostic within 10 minutes after one of your “events” and post the confirmation number here. Extensive data about your wireless environment is logged in the diagnostics, but only SONOS staff has access to this data.

Is your issue associated with one particular player? Time of day? Number of active players? Are any of the players bonded as a Left/Right pair?

If it is practical to wire one or more players to your network, try this configuration after submitting the diagnostics.

Hello. I have had a sonos play 3 for about 4 years and I haven't turned it on for 2 months, and now the power light doesn't come on. In conclusion, it doesn't start anymore.Do you have any idea what happened and how I could solve this problem?

Likely there is a hardware issue. Make sure that the power cord if fully seated in its socket. Otherwise, you’ll need tp contact SONOS support.

In addition to the advice above, it would be worth double checking that the wall socket it is plugged in to also has power.

Thank you very much!