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The amp has no power. Is there an internal fuse for this unit?



Has anyone taken one apart?
Ahhh yes, that would do it 🙂
@benbendog, Congrats... "Bob is your uncle"



Always good to hear when someone fixes it, because Sonos won't 🙂 Nice work.
Is there anyone here that is willing to repair a ZP100 or ZP120. I am on my 2nd iteration of each of these. One was replaced out of warranty by sonos (thanks), the other not. I know the end is nigh. Thanks
They are varistors. Part# TVR14241. So far, the only place I found them were on AliExpress. Your amp will work without them but I wouldn’t operate it for too long as they are there for protection.
Hey Toden,

You probably have this fixed already, but if not the 74VLC06AD on mine was bad. You can download the datasheet and buy them from the link below. From the datasheet look at the pinouts and measure the outputs to ground and see if any are low resistance like 100 ohms or so. One of mine was, and that fixed my problem.

https://www.mouser.com/ProductDetail/Nexperia/74LVC06AD118?qs=sGAEpiMZZMutXGli8Ay4kDE4J8KCiPsFeMuB44hEVa8%3d



To anybody else, I have a repaired power board for sale on ebay. Let me know if you have trouble finding it.
Re my ZP100...



The problem it had was that it was not getting any output on the left channel, and within the app it was detecting a fault. This fault caused it to reset the volume to low levels. This made it unusable as an AMP and also not particularly useful to use the RCA outputs. (I'm not sure -- maybe I could have set those to fixed output -- not sure).



In any event, I opened it up today and couldn't see anything wrong with it. However, during my poking around inside, I must have bridged something... I think It was from the AC to DC board to the chassis as I tried to measure the DC voltages there. There were fireworks and popping. I quickly unplugged it.



The interesting thing (to me) is that it is actually more usable now than before! I took the whole thing apart looking for blown capacitors or anything similar. The only thing I found was the both STA505 chips were quite obviously blown... they both literally had pins missing/blown off (see the image). I figured it was very dead and reassembled it to prove it. Lo and behold... It booted up the first time. Not only that, but it stopped throwing faults! There was no audio on either speaker (not surprising given the amp chips were dead). BUT... both RCA outputs were working. SO despite my boneheaded mistake, I now have a device that can at least be used as a sonos connect (no AMP).



I'll probably try to replace the AMP chips. I have two STA508s. These are the chips that are used in the ZP120, but they are pin for pin compatible with the STA505s that are used in the ZP100. I imagine that even if I am successful in replacing the AMP chips (no small task), there is a high probability that there are now other problems on that board, given the fireworks. On the other hand, the blown pins on the amps look to be only the positive and negative supply pins (4,5,6,7,12,13,14,15). If the board traces survived, maybe all the damage is isolated to the amp chips.
Piperdog,



Have you ruled out a problem with the low pass filter (LPF) of the class D amplifier? The noise you hear may be "switching" noise leaking through the LPF...the electrolytic capacitors may need replacing.
Hi Sotisg69,

Well if you’re original problem is gone but now you have a new problem, I would definitely resolder the pins of the new IC. Maybe take a magnifying glass and see if you have good solder flow on each pin, and more importantly make sure you have not bridged and pins with solder.

After that when you push play, make sure your 36V test point on the bottom of the power board goes from 15V to 36V.

If all that is ok, there is a pre-amp chip between the logic board and the power amp ICs. It has a mute pin that you can see if it is stuck. But it’s unlikely. More likely your already on the right track.
I misled you. I forgot to reconnect the ribbon cable from the front panel controls! It attaches to the logic board directly below the Wi-Fi card. The controls now work fine. Your reply made me rethink what I had done. 🙂
I lifted the shield can and connected to the UART -- here is what I get.

So I don't forget the pins are vdd,rx,tx,gnd …





U-Boot 1.1.1(1-16-3-0.9), Build: 0.9



MPC8272 Reset Status: External Soft, External Hard



MPC8272 Clock Configuration

- Bus-to-Core Mult 3x, VCO Div 4, 60x Bus Freq 16-50 , Core Freq 50-150

- dfbrg 1, corecnf 0x10, busdf 3, cpmdf 1, plldf 0, pllmf 3

- vco_out 400000000, scc_clk 100000000, brg_clk 25000000

- cpu_clk 300000000, cpm_clk 200000000, bus_clk 100000000

- pci_clk 33333333



CPU: MPC8272 (HiP7 Rev 14, Mask unknown nimmr=0x0d10,k=0x00e1]) at 300 MHz

Board: Sonos Wembley

DRAM: 32 MB

DRAM test

Test complete - 1 errors, error pattern 00400000

### ERROR ### Please RESET the board ###
That's a bummer. Which Hakko do you use? I need a hot air tool. Crazy range in prices.

Remind me what your Amp was doing, or how it was failing?




I use the hakko 851 -- it is one of their pricier ones. I have nothing to compare it to, because it is all I have ever used. My amp was the blinking white light. After debug I found that it was stuck in the bootloader due to the dram memory test failing.

There were some smart people posting in this thread. Hoping they are still around. 


I figured to grab my other broken Sonos amp from storage and I didn’t notice it when I bought it but it looks like the previous owner already opened id.

The fuse was open, and the solder points looks very shady, so either he replaced the fuse or only tried doing so.

I had a pair of fuses lying around so I quickly replaced it, reassembled everything and once I plugged in the power chord my lights went out and I could smell electronic burn 🙂 xD 

Is this a case where it’s appropriate to use a bulb? A friend of mine told me to hook up a bench power supply (with very low voltage) and trace the signal from there.

All other components looked good, from the look of it.

BTW How can I figure out that the 110v/230v switch is ok and not shorted?


Wow, that shot with the light behind the PCB was amazing! Well done!

I forgot about that coupled inductor. That guy conducts ALL of the primary power. One small nick in that mag wire will cause the inductor to blow open and no voltaje, in a very ambiguous way. 

So given where you are, primary power restored, i would get a datasheet for the bias converter PWM and get to work. In this thread there are some nice test point references to show you what you should get with a working unit. Take a good look around the PWM pins on the bottom for corrosion.

Pro-tip: the bias converter is a very standard flyback converter. If you google flyback converter you will get something similar to what you have in the AMP. Look closely in the primary winding snubber. Also check the 10ohm high wattage through hole resistor, it provides power to the transformer primary.


 

All. voltages seem good EXCEPT I never get 36V between GND36 and 36V it sits at ~15v. When the volume is turned from 0 to anything I get a blip of sound (quick drop to 13-14V) and then orange flashing light, with the volume bar jumping back to ~15%. 

I suspected the 14 pin IC on the logic board gruv2ths mentioned solved his similar issue. I swapped the entire logic board with a known good one and same thing. 

Where is this 36V supposed to come from? Do I have a switching issue? voltage issue? OR are the amp chips gone?  Need a push in the right direction to identify what's failing. 

The 36V only becomes active above a certain volume threshold.  I found some sonos patent information a while back - this approach is what allows the unit to be low power until higher power is needed (ie when it is actually amplifying), and this is why leaving them on continuously doesn’t create a lot of heat or use a lot of power.

So the 15V you get at the 36V point is ‘normal’ when the device is in standby or at low volume, but when you hit play or turn up the volume then the 36V should come alive and the 36V point should read 36V.

I believe that the 14 pin logic chip is what controls the on/off status of the 36V.  That is located on the top logic board.  I recall gruv2ths saying somewhere that some of the 36V control circuitry (perhaps a recitifier) is on the riser board.  You might try to swap that riser to a known good one and see if your problem goes away or not.  Once you have the top logic board removed, the riser just pulls straight up.

I think that if the amp chips are gone, then they could be causing a short that is affecting the 36V.  Hopefully that’s not the problem.

 


Thanks Tim. When I tried the other logic board, I didn't swap the riser board! will have to try that, wasn't aware of any control circuitry there. 

I'm leaning towards the amp chips, but would really like to know if they were shorted would the problem present itself as it is? 

Should the 36V be available anywhere on the board while in standby? 

If I remove the amp chips should the 36v present itself once the volume is turned up? 

This photo is from 2 years ago from this thread from a user that I don't think got to the bottom of his issue. The hilighted area as I understand is the 36v supply? 

It’s hard to know what symptoms a blown chip would cause.  I once had blown amp chips that went in such a way that they lost some of their pins in the process -- literally blown off.  In something like that, the traces could be damaged, it could cause shorts elsewhere… It’s just too hard to know for sure what to expect.

That section is the 36v supply.  If you are familiar with the primary side voltages, the power path from input 120/240v is rectified and passed through a dual inductor and 320v dc is produced which is available on pin 5 of the primary side of the tarnsformer.  Somewhere around the mosfets that are part of the doubling circuit that generates 320v, the circuit apparently branches and feeds into the 36v supply section you identified (I’ve never looked at where this happens in the zp120).

I just looked at that section on a board… it does look fairly straightforward.  What I mean by that is that it should be possible to check many of the components.  Bad diodes, capacitors or even open windings can all be looked for in circuit.  The 3 pin devices that look like transistors are actually dual diodes and those diodes can be checked too (use diode test between the middle leg and each of the outer ones).

I have some zp120 devices that have the same symptoms you describe -- i just haven’t invested time in looking much further at this point.  I have fixed a lot of the older zp100 devices, and they had similar voltages.  In those, the 36v would be unavailable when in standby and i think the zp120 would be the same.

Please post back here is you find anything (good or bad).

 


ITS THE DAMN RISER BOARD! I'm so happy, and at the same time mad at myself for not trying that when I tried a known good logic board. 

with the repaired power supply, known good riser and existing (from the bad unit) logic board, I got my 36V and sound. 

Now to dig and compare what's wrong with the riser board, or buy one of they're available. 

 


That was it! I replaced the shorted diode with a 1n4148 as that's all I had on hand. No more orange light and she sings! 

 

I have to thank everyone that participated in this thread, wouldn't have gotten her working without your help. 

 

Congrats!

It looks like that component may be a zener with a working voltage of 2.1-2.3V (google philips bzx399).  The 1n4148 is a switching diode, so it might behave a little differently.  For example, the 36V section may be constantly ‘on’ rather than off during standby.  If you get any more issues you may want to find a more similar part.

I had a quick look at my units that have been having similar issues, and sadly this part is fine on them.

Thanks for closing the loop on this. 


Here’s a similar issue that your info helped me solve (I’m 99% sure)...

This is the same board that I posted an image of a couple of days ago.  I had replaced some damaged components, and after that it would do the white/off/yellow/off cycle when I tried to play.

 

The 2 traces that run vertically between the transformer on the left and the two grey capacitors on the right connect two pins from the riser connector up to the MOSFETs above.  They are damaged (confirmed with a continuity check) - it looks like the power surge the board suffered must have caused them to blow up.

I wouldn’t have found this so quickly without your success, shtnarg!  I imagine I’ll have to replace that crispy looking R16010 on the top right as well -- it seems to be in the path back to the riser connector.


I'll check if the 36v turns back to 15v at standby. It's only temporary until I find the matching part..

Have you tried yours with a known working riser board and logic board? I'd like to still know more about the orange light error. Seems with all voltages correct the orange light refers to the riser/logic board or amp chips.

I have a Gen 2 Play 5 that has a short on the power supply. Doesn't seem to be much info out there on them. 

Yes I have seen the 36V fall back.  It doesn’t happen immediately but it does eventually.

My issue is on the power/amp board - see my other recent post.

I have a few gen1 play:5s but no gen2.  The gen1 play5s are actually pretty horrible to try to fix.  There is a massive buildup of heat in them when they are in use, and it causes a variety of different failures.  The enclosure is basically a box with only one small bass reflex opening -- not great for air circulation.


I put mine back into the shell to clear it off my desk. Forgot the volume/mute buttons, so I did that twice, including those F****** clips! 

And of course the orange light is back. 

Third time’s a charm!


 

Well, no joy - but oh so close…

It booted up ok, but when I hit play I still get the white/orange cycle.

I’ll keep looking but honestly I’ve been through this one pretty thoroughly so don’t know what to look for any more.

 

Actually… I feel so dumb… I still had my dim bulb in the circuit.  Once I removed it everything worked beautifully!

I fixed all four zp120s that I described 10 days agohttps://en.community.sonos.com/advanced-setups-229000/repair-zp120-17442?postid=16419707 .

This included one with multiple rusted traces, another with a rusted transformer winding, one with two bad schottkys, and one with a bad PWM.  There was other collateral damage too (diodes, caps, etc) but those were the dominant issues on each.

I also tried fixing a wifi/logic card, but was unsuccessful.  I had one card that showed a dead short, and another that had a bad NAND chip.  I moved the NAND chip from the card with the short to the other card, but it wasn’t recognized.  It turned out that the good chip was ‘legacy’ and was a 64MB chip while the other NAND that it was replacing was ‘modern’ and was 128MB.  It gave a message of ‘no NAND found’ in the UART, so I’m pretty sure it just doesn’t recognize the chip.


Fantastic - Nice job!


Thanks, will check it out!


Hi, can anybody tell me the vale of resistor R15550, located under the WiFi module on the ZP120?

This component is missing on my board ( knocked off and lost by previous “repairer”). Oddly, the player still works, but I would like to replace it.

 

You’re in luck!  That’s a 0 ohm jumper, so no parts search required...