Repair ZP120


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

Has anyone taken one apart?

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Hey man,
Yes your frustration is defiant understood by myself and M0untainman.
So to unsolder the transformer leads takes patients. Lol
I do it in 3 steps.
1) wick out as much Sonos solder as you possibly can.
2) Now flow in as much of your solder back into each hole. This will help transfer heat to the stubborn Sonos solder that is left.
3) wick it all out.
4) on the still stuck pins I get with the iron and wiggle with a tweezer as you remove the heat. This will hopefully keep the solder from cooling back on the pins.
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Hi gruv2ths,

I managed to get the transformer out but I did a horrible job that I broke off a few PCB pads (should not be a bit deal since worst case I can use wires to connect them back). On the primary side, there are total 8 wires coming out of the transformer that I lost the ordering after taking them out. I took a few pictures to show what I have. Can you take the same from your working one?

I probably will need to get a working one from you anyway.

Thanks,
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Dude! One word comes to mind.... Butcher!! Lol jk
We all had to learn sometime.
I will say that I am concerned about the damage to the pcb. The reason is the high voltage on the primary side. They can midigate creapage and arching in the pcb, but with jumpers all bets are off. So let’s hope we can clean that up, without any fireworks. Dim bulb will be helpful I terms of delivering current to a short. But then again with those huge storage caps across the 300 volts, definitely tread lightly.
I think I know of the unit you are working on. Was it recently on eBay? $100ish no bottom. (Well the bottom mounting chunks were still there) yes if you look closely in the eBay pic you can see the ripped off WiFi connector. I thought long and hard about talking a risk in that one.
I have a bottom and the WiFi antenna for you if you need it. I can give you a package price with the transformer if you like?

Will send the transformer pic later this afternoon.
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So here are a few pics that may help. This is the bias converter transformer that I have for sale if you need it.
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Hi gruv2ths,

Thank you very much for sharing the pictures. My secondary winding are still intact and I need mainly to figure out the primary connections. I think I got it from your pictures and I will give it a try.

You are correct this is the eBay sell with broken bottom. I cut a deal with the seller for $70 and I was willing to take the risk just for fun. 🙂 The condition was not as bad as I thought since I can see nobody has tried to fix it and the damages are all mechanical. I hope will fixing the transformer it can be back to life.

Please give me a price for the transformer as well as with the bottom.

Thanks again for the help,

-Tao
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Hi gruv2ths,

With the help of your pictures, I think this time I did an OK job recovering the transformer:



All windings now have expected connectivity and resistance. My plan is to flip the transformer (pins sticking up), glue it on the PCB, and use coated wires to connect it back to PCB. That way I can easy fix it in case something happened during the soldering process. I will keep decent gap between wires.

I will keep you updated.

Thanks again for the help,

-Tao
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Nice... so it was the pins :-)

I am very very hopeful this is gonna work for you... can't wait to hear!
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Hi Guys,

I managed to install the fixed transformer back to the power supply board:



I double checked all the connections then powered on. I was using RTN1 (pin1) as GND and I did get 3.3V output which means the primary is working now. On the other hand, if I use the same RTN1 or the CPU_GND, I got nothing from either the 8.4V or the 15.4V. I then switched the GND to RTN2 (pin3 of the secondary) and I was getting ~7.8V and 14.8V from both outputs. I was really happen to see that. It seems that the 3.3V and 5V/14V don't share the same GND. I remembered someone suggested to short them together but I was not sure if I should do that if by design they are separated.

I was very excited to put everything together and powered on. The good news is nothing blow-up but the bad news is the LED didn't turn on. I will have to debug it later. I am not sure if it is related to the GND connection.

Thanks again for all the help so far.
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That's great news. Now IIWY, I would be sure those leads are coated. Get some liquid eletric tape and slather them. The reason is the electronics on that board are really not friendly to shorts. That PWM blows by just looking at it and its a tough part to get. Both gruv2ths and I have blown those multiple times.

I believe it was gruv2ths who said you could short the two RTNs and all should be good.

Let us know if its all working... its great to hear when we get one up and running. 🙂
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Hi gruv2ths,
Can you confirm if I should short the two RTN points?

Thanks,
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NVM, after putting everything together, now i can see the two RTN points are shorted probably by the main board. I will do more detail measurements tonight.
Wow, that was a long but interesting read. I have a ZP120 with the "stuck on white LED", no ethernet traffic. It looked inside and nothing obviously damaged. I rung out the front panel board and everything looks OK there. Should I start another thread? Any ideas what the white LED means? It comes on within a second of plugging and just sits there.
LED States FAQ
LED States FAQ

Thanks, I have done all that though (factory reset, hold power + v+), etc … and the light just stays solid white. And none of the ethernet lights on the back are blinking.
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Hi guys,
I have a great news to report, I found I was shorting the transformer contact after I installed the mainboard, I was really lucky nothing damaged. I isolated the contacts and guess what, the white LED turned on right after power on! It took me no time to add the zp120 to my Sonos setup and it is driving my KEF speaker replacing the Arcam:



The white box under the table is the zp120, the one one the small table is the zp90.

My next steps are to put everything together and fix the wifi antenna.

Thanks again for the help. I like this forum, I hope with my little experiences, I can help someone in the the future.
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Congrats!! Feels good right?!?
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Aynamne, use the cheat sheet I made above and see if you have any of the bias converter working.
There was another guy on here with the same symptom as you and I think he gave up. Not sure what causes that.
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@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
My sonos ZP120 got wet with soft drinks by accident, I'm in the process of soaking in all these information. I shall try to fix it myself fingers crossed. Thank you very much everyone for creating this forum.
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All, great thread running here.

I'm wondering if I can drop a question in here rather than starting a new thread? Does anyone have a view on the various ceramic caps in the zp120? In particular would anyone know what I would need to replace the two large yellow ceramic caps that are located between the two storage caps with? they appear to be labelled D16033 and D16034. Thanks for any help you can provide.
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.
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Thanks @noguruhere! Appreciate the response. I don't suppose you know what the green ones are to the right hand side of the right storage cap do you? The ones between the bridge rectifier and the grey resistor show in the first image I posted? Thanks again!!
@brumster, yes those are thermistors part# SCK-054. Also hard to find here in the US.. I’ve found those on AliExpress as well.
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Thanks again. Appreciate the help!

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