I would contact Sonos Support:
https://support.sonos.com/s/contact?language=en_US

Also try unplugging the cord from the Sub end, that can work loose over time if it wasn’t fully inserted.

Sonos has a good reputation for helping folks out of warranty if the unit hasn’t been tampered with.

I tried different sockets, different power cable, but unfortunately the sub is dead, no even a blink from the LED.

Yesterday I contacted Sonos, about 70 min on the phone, but we found no solution. So I don't know what to do, my sub becomes a very expensive brick!

Now I don't know if I buy a new one, knowing that the product lifespan could be only 3 years or less, so frustrating.

I know it is out of warranty, but it seems to be also unfixable...

It must be the older Sub (gen2) as the gen3 was released June 2020, I believe - Did you ask about a trade-in, or discount? My thoughts are to take any discount offered and with any saving, take out extended warranty insurance to cover the new Sub for perhaps a number of years beyond any manufacturers warranty. It’s why such insurance policies exist, I guess.

I have bought Sonos devices through Amazon as gifts, getting a 4 year extended warranty as a package deal. Sucks to have to cut Amazon in on the profits.

I did get a suggestion to see about getting an extended warranty from Costco, apparently they will sell one even if you bought your device elsewhere.

I sure wish Sonos would do a partnership with one or more extended warranty companies.

I talked to the Service team after I posted here, you are right, it is the Gen 2 (the product itself didn't mention the generation).

I asked for some kind of trade-in or discount, but they didn't provide any, so I guess I will need to buy a new one and find some useful use for the broken one, maybe convert it into a passive sub for a non Sonos system. A discount or some kind of trade-in will be more than welcome and it will help me to be brave enough to buy a new one.

It seems to be a really good idea and suggestion. I will consider it for my new products.

The one that is broken I believe I bought from Best Buy, unfortunately I don't remember where I put the receipt.

I use Sonos I believe since 2015 and this was the most expensive product I bought from them and the first one to show a problem. The Playbar, Beam, Play:1 and Ones I bought during this period never show any sign of problem.

Thanks for all the help and suggestions!

@JorgeQueiroz,

Have you perhaps searched online to see if there are any 3rd-party services who may be able to repair your Sub. I’m in the U.K and such repair services are supposedly available here (I’ve not had occasion to use them - touch wood), but maybe check your local area. If not, then you may find you can perhaps sell it for spares or repair and try to recoup some of the cost.

If you log into your Sonos account online and check under Upgrade your Sub Gen 2 should be eligible for a 15% discount off a new Sonos product.

If you purchased it from Best Buy, and used an ‘account’ to do so, they should be able to pull up a receipt for you, even for open box products. It’s actually one of the reasons I use a Best Buy account, since they don’t seem to provide any real discounts for account holders.