There’s no way you could add a Boost. It would ship with a much more recent software version (of S2). 

Are you sure the Bridge itself has died? Normally it’s the power supply which gives up. If you have access to a meter a health PSU should put out a steady 5.1V or thereabouts. There are third party compatible PSUs available.

If the Bridge is really a goner your choices are to keep another device wired instead or to switch to WiFi (‘wireless’) mode.

Thanks for that, just about to check the PSU. I have an alternative that gives 5.5v / 2.2a which should be within tolerance. There are second hand bridges out there, but not sure if they are also software version hooked, or independent.

The market has been awash with Bridges for years. For a time they were given away with every speaker purchase. 

Finding one with exactly the same ancient firmware version could be well nigh impossible. Even if it was at v8.4 then the process of adding it would require registration with your Sonos account which could risk a firmware update. 

Yes, good point ratty. I have aquired a number of CR100s and used bits of them to keep the old ones working and as you say, even with 8.4 versions, it does not seem possible to hook them up. Still, an old bridge may be useful depending on whats failed on mine, unless its the psu, in which case happy days.

So checking the PSU it gives a fluctuating value between 4.99 and 5.07 volts (might be because the meter does not give a load but I don’t think so), so I’m going to try another PSU and see if it works.

The voltage should be steady. Fluctuation suggests it’s an ex-PSU.

Ok, have now tried it with a different PSU and believe the bridge is a gonna. A couple of days ago, when the Sonos system stopped working, I discovered that I had a network (broadcast) storm. I’d had one years ago and bought a new managed switch to sort the issue as I needed a wired speaker in the garage block plus wireless in the office.

So first thing I did was disconnect the garage wired speaker and the storm stopped, but could not restart the Sonos system. Its taken a while, but got around to substituting the ZP for the bridge and the Sonos system came back to life (after a little faffing around).

Having put a new PSU on the bridge and reconnected it, bang, another broadcast storm so I’m thinking the bridge is toast. I’m going to see if I can get one of the other Sonos components hooked up as a bridge for a more permanent solution. I may have to buy a couple more manage switches as I run the Sonos over 3 buildings.

Hold on. If you have another wired Sonos device and resurrecting a functional Bridge triggered a storm you have an STP problem, not a Bridge problem.

Is the Bridge the sole wired Sonos device or not?

Bingo, actually managed to find a use for my old ZP80 that got left behind at version 8.2, it will act as a bridge no problem, just can’t be used to play music without the update (which is impossible to do).

The v8.2 ZP80 may cause controllers to nag remorselessly. 

It would still be good to have an answer to this question.  A broadcast storm should do no permanent harm.

CR100s don’t know how to nag (or at least they have not so far).

WRT the storm, the set up has been unchanged for 6 years after I bought the switch below and set it up to sort out the storm that originally occurred when the man cave was build (see below). To go into a bit more detail, the ‘bridge’ (or now the ZP80) is located in my office and hooked up to a Netgear GS108Tv2 switch. That switch connects to another switch in the garage block (aka my man cave) over Cat 6 wiring. Its too far away from other buildings to get a WiFi/Sonos Net link.

Similarly, a separate Cat 6 cable runs from the office to a switch in the house that in turn connects to the router (again distanced is too great for WiFi).

So in effect the ‘bridge is ethernet connected to the router. In the garage I have 10 play 1s hooked up as stereo pairs, one of which is wired to the garage switch mentioned above. This is the layout that cause the storm 6 years ago when I was using an unmanaged switch in the office. Using the settings on the managed switch sorted out the issue and all has been good until 2 days ago (yes, I agree the storm should not/would not have damaged the bridge, but I think something has gone wrong with the bridge to cause the storm - theory only).

Having now swapped the bridge out and the ZP80 in with the rest of the topology unchanged, everything is now working normally (Sonos, WiFi , and the cabled network). So, although I cannot prove its the bridge, I can say that if I connect it, a storm occurs almost immediately, with it out of the picture, all is fine.