Play 3 Powersupply fault.

Userlevel 3
My Play 3 died the other day and I am just outside my warrenty period 😞 I contacted sonos customer services who did not help me in the slightest. I have now looked at the power supply board and seen that the board around one of the input capacitor has burnt out and or the cap itself.

As customer services won't even sell me a new power board, does anyone have a circuit diagram for this board so i can attempt to repair it myself. ( I am competent with electronics).
P/N: RN-002657 (board number)
Date: 08-04-11

Also has anyone else experienced this fault. I am assuming a power surge has done this.

Many thanks


This topic has been closed for further comments. You can use the search bar to find a similar topic, or create a new one by clicking Create Topic at the top of the page.

103 replies


First post! Welcome to the forums.

SONOS does not support DIY service in any way. I know that this policy chaffs some, but it probably eliminates some legal risk and saves a lot of time supporting DIY's of various skill levels. SONOS is not unique for establishing this policy.

Burnt traces and capacitors are usually the victim of a larger drama.
Userlevel 3
Thanks Buzz,

Yes I guess its probably the best policy for them.

I guess I will be getting my multimeter out and spend some time figuring it out. Doesn't look like a complex supply so should be pretty easy to find the fault.

I will keep posting my findings

Userlevel 3
In continuation to the above,

Upon stripping down the play three which proved pretty easy due to its modular design, the issue with the power supply board was the capacitor (C306) had exploded. This is the smoothing capacitor post bridge rectifier. When this exploded it also took out the PCB track sandwiched between the board (multilayer PCB).

After bridging the broken track and replacing the Capacitor with another 33uF 4ooV from RS, the supply was tested and all good.

My Play 3 is now back in action.

Thanks for the follow up.

Did you monitor the temperature of C306 for a while after the repair? I doubt that the original capacitor was the generic type that one would expect to find at Radio Shack. If the ripple current is beyond the replacement capacitor's capability, you'll be repeating this exercise again.

I expect that there are small capacitors across the bridge rectifier. Did these look OK? If you have a second PLAY:3 and a portable AM radio, place the radio near the repaired PLAY:3 and compare the emissions with a never repaired PLAY:3 (this is tricky, be sure to use identical relative positioning for each test) If emission from the repaired PLAY:3 is substantially higher than the never repaired unit, be suspicious. Of course you could have more emissions because of a simple re-assembly issue, but there might be more.
Userlevel 3
Having soak tested my play 3 for a few month, I can confirm that the fix worked with no other issues. Thanks Buzz for the useful tips. I managed to source the same capacitors and looked at the balancing of the old verses new. All seems fine and not problems with noise etc.

I have recently been contacted regarding the above issue happening to another Sonos user. Unfortunately, as i have only posted 3 times I cannot reply to you privately however I hope that you can view this link to a few photos of the circuit diagram and damage to the board.

Let me know how you get on.


Userlevel 3
Userlevel 1
My sister has several Sonos components, but when her relatively new (but out of warranty) Play 3 died she has become concerned about overall Sonos reliability and Sonos support.
She contacted Sonos who told her it would cost her around £120 just to look at her Play 3? Interesting approach to customer support for a high end product!
As I am a bit of a dab hand with electronics I agreed to take a look for free! Having dismantled the Play 3, I discover part of the PSU board is burnt out, sounding familiar? Is this a common mode failure for the Play 3 or Sonos units in general?
I was interested to read this post as it seems to follow a similar trend, are there more out there?
I will investigate further and advise what I find with regards to the actual fault.
Is this a common mode failure for the Play 3 or Sonos units in general?
Not that we're aware of, and some of us have been hanging out around these forums for a number of years. We're pretty familiar with the main failure modes for each unit, and PSU burn-out is not one of them. In fact, I'm not even sure that there's any consistent pattern of failures for PLAY:3 at all.
Userlevel 1
That's reassuring to hear, although this does surprise me seeing the nature of the failure, which looks remarkably similar to the photos posted by Jamie! I will try to post some of my own. Better these things are brought out into the open!
Each unit has its own failure signature and signatures vary over the life of the unit. Actually, repairing units (of any type or manufacturer) when something turns color is easier because this is a broad hint about what's wrong. (It not as much fun if the printed circuit board is damaged) The burnt part is usually a victim, not the cause, but it is still a helpful hint. The wost type of failure is a low duty cycle intermittent. It takes forever to locate the failure and verify the fix. Once the signature is known, if one sees enough of this intermittent model, you'll just apply the fix whenever one of these units is encountered.

Servicing is quite similar to a hospital. After a quick walk through it's easy to come away thinking that "everyone" is sick -- and they might all have the same problem. Even if a very small percentage of a given model fails, there can be quite a pile of a popular item in the national service center.
Userlevel 1
Upon investigation I find that the date code for my sisters PSU board is identical to the one for Jamie who previously reported this problem. Same burnt piece of pcb too.
C'mon guys we weren't born yesterday and some of us have sufficient knowledge of electronics reliability to recognise a common mode failure.
I now have exactly the same problem with exactly the same place burnt out on my board as the drop box pictures by Jamie and the same board number no coincidence I feel!! Board date 08-04-11
By replacing the pot was everything ok as it looks like some of the PCB blown too ?Why cant Sonos provide a complete board change as an electrician I am always doing component changes on boards. Can anyone assist with a new board?
Userlevel 1
Hi Wiggy, this hardly surprises me. I am a specialist reliability electronics engineer and I recognise common mode failures when I see them. Manufacturers usually want to avoid liability issues so they tend to simply deny everything, as we have seen here. Most of us want to just get our products going again, not pursue litigation.
SONOS adopt a policy of not supporting third party repairs so they do not currently supply replacement boards, but if enough of us complain they might just listen, or least provide circuit diagrams so that we can see what needs to be replaced. Are you reading this SONOS?
My board is so badly burnt that the inter layer tracks have burnt out so replacing the capacitor didn't do the trick, I have been to busy to investigate further, but will be interested in yours or anyone else's experiences!
Userlevel 1
I picked up a faulty play 3 for a tenner the other day. Heck of a deal.
Cracked it open and turns out I have the same power board revision as what jamietaylor13 posted except my capacitors were fine.
Turns out the digital power switch literally blew its guts out. Likely through a power surge. I heard rattling as I was dissasembling and it was the top of the chip exploring it's new-found freedom inside the unit. Fortunately the chip number was still visible on the little cap bouncing around.
It was a Fairchild Green Mode Power Switch model number FSQ0565R but none can be had outside of 1 month shipping from China so I found the next model up FSQ0765R which is pretty much the same except a little beefier with power handling. Ordered one off fleabay for 6 quid and arrived next day. Today I soldered that bad boy in and still had no power so I had to start tracing back the power source and found that the fuse had also blown. It's the tiny little brown cylinder near where the 240AC enters the PCB. I soldered a temporary bridge (yes, I know, leave me alone) and woila! working!
Anyway, I thought my experience may be of help to someone else out there.
Good that some DIYers' could fix the above problems. I did something similar once in the days when computer motherboards had components tat wern't surface-mounted. I dgress though. My point is that the "expensive" look- at costs are not that. Sonos REPLACES your gear for that price. I had a 6 year old ZP100 die and received a new Connect for a fraction of the new prcie OK so I lost 2 ethernet ports but I still only use one. So I am I grumbling? No Way! I could not be happier with SONOS support. I later bought 2x Play1s' Which I thought sounded great the hearing of the EU price hikes bought a Sub. Now I am over the moon. And no I dont't need a headphone socket on my gear.
jamietaylor13's fix worked in my sonos play 3.
Replace the exploded cap and wire the + lead of the bridge-rectifier to the + of the replaced capacitor.
Works perfectly
Here is another guy that was able to repair a play 3 with jamietaylor13`s fix.
My play 3 died under penetrating smell.....

After opening I saw that capacitor (C306) was exploded and cracked the conducting paths around.
I unsoldered C306 and bridged the + lead from C319 to the + lead of the bridge-rectifier and measured power at the connector to the motherboard.

So I ordered and replaced all three capacitors wired the bridge rectifier to C306 and my unit is working again.

Thanks a lot for this guide and especially for the pictures and the wiring diagram in your dropbox!
Userlevel 1
Is there a problem with a batch of Play:3's as mine has just stopped working., It has that distinctive burnt electronics smell wafting from within.. I have a support call open with SONOS so I shall await their response before cracking it open and trying to repair.

I wonder, should they issue some kind of recall as there could potentially be a fire risk to one of these units?
I doubt that there is any fire hazard. A small part can emit quite a stench when stressed, but not present any significant hazard to life or property.

It seems that this is a failure mode of PLAY:3, but here we have no idea how many have failed in this manner. It is possible that all of the failures have been reported here or only a fraction. We simply don't know. We also don't know if there are contributing factors to consider -- such as ambient temperature, power line voltage, hours of use, orientation, etc.
Userlevel 1
well after being quoted a large amount just to look at it (out of warranty) I have opened up and checked. I am very competent with electronics and repair although the more modern the electronics the more tricky this can be. The exact same capacitor blew on mine C306 , same burn marks everything. It has burnt it's way through the board too so I'm sorry there is a definitive risk of fire hazard there. Considering we're advised to leave the devices running in the manual I don't think this can be right. Even if it's a bad batch with the same capacitors used. My part number for the PSU is RN-002657 Dated 08-04-11. I will be checking my second Play:3 to see if I can prevent the issue there.
Userlevel 7
Badge +22
I guess if you're concerned about its safety you should take it the Trading Standards (UK) or whichever is the relevant safety body in your region.

But I would say that just because something fails in such a way as to generate heat and discolouration does not in and of itself self imply the whole was at risk of fire.
Userlevel 1
suppose.. but makes me think twice about leaving them on now , that's for certain.
Userlevel 1
Repaired, luckily the board was not damaged beyond repair. I had to make a new rail on the negative side of the capacitor/rectifier where it had burnt through as it was a sandwiched PCB board with a central layer. I've put in three new higher temperature rated capacitors to replace even the ones that did not blow (they too look slightly enlarged however). Bench testing now for observations.
I have the exact same problem on my Play 3, same code too: P/N: RN-002657 (board number)
Date: 08-04-11. Will follow the guide and replace the capacitor.
Exactly the same problem here. Replaced all three capacitor and bridged the + lead from C306 to the + lead of the bridge-rectifier. Also had to replace the fuse F301 (that little brown cylinder reading T2A). Don't forget to check that fuse. All working fine again. Costs: 10 euro (I bought higher voltage/better quality capacitors) and some hours instead of the 180 euro Sonos offered me to replace my PLAY:3 witha new one...