Repair ZP120



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Hi
I hope there is someone who can help me.
I have a ZP120 that flashes orange and white.
It will not play music, but if I hold the mute button for a few seconds, I can make it light dimmed white and I can play music.
But only for 2-3 minutes, then it pauses again and starts blinking orange and white again.
I have had it apart and there was a little corrosion on the print card, I have cleaned the corrosion and I could not see that something was wrong with the print.
Does anyone have an idea of what it can be?
Hello.
I have almost the same problem as runecal. i have 6 amps that have gotten overvoltage. i have changed the 2 large caps. and a little thermistor and the fuse.
i bootes up and is connected to network, but when i tries to play music, it turns to blinking orange.
any idea???
Really great documentation here, well done!
Couple of observations.
-if you are getting the 3.3,8ish,15 on the secondary then the bias converter PWM is working correctly.
-The reason you are seeing 0V on the transformers pins is because you are looking at AC with your meter set to DC. Those biases measured in the logic card say to me that the bias converter is running and the output is making its way to the logic card. Good sign
-I can only think of one thing left to do, and that is measure the output of the buck converter on the bottom of the logic card. There is a inductor with a (normally) yellow electrolytic cap. Solder a wire to the striped side of the cap and put the card back in and plug in. You can put the red lead on the wire and the black one to chassis. Should have 1.5V output.

Do you know much about reading serial (UART) from a computer? You may have noticed a 4 pin header under the EMI shield that you removed. There may be some diagnostic clues coming out of that serial headder.

The one I am working currently has a confirmed good power and riser boards and shows up in the Sonos app but when you push play I get orange and white blinking leds. Wanting to read that header and see if it can give me a clue as to why mine shizes the bed when I push play.


i have 4 amps, that goes flashing orange and white when play is pressed. have you got any luck on that issue???
Blinking orange and white is fault mode. The Amp is either too hot, or there is a short. Make sure there is adequate ventilation and check that the wiring is not frayed or sticking out, causing a short.
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Toden,
The flashing orange on mine was due to a bad driver IC on the logic card. It is a 14 or so pin IC.
Mine would flash orange and white when i push play, the app keeps playing like nothing is wrong yet no sound from the amp.
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@brumster, yes those are thermistors part# SCK-054. Also hard to find here in the US.. I’ve found those on AliExpress as well. Any chance you have a part number or a alt part for the large 1000uF storage caps on the front end? Thanks!
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I have for sale, 3 Connect:Amp power boards with chassis and bottoms (wifi antennas and white plastic pan) that are tested with a known good logic board. I can send you videos of them working with a pair of JBL towers.
You just drop in your logic card and your in business.
Message me at gruv2ths@gmsil.com if your interested.
gruv2ths,
do you have more info about that ic, model, pictures, where to buy
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Which IC?
you wrote about a bad driver ic on the logic board, you succesfully have replaced.
just to be sure, witch card is the logic board. the one with ethernet or the one rising from the powerboard
gruv2ths,

you wrote about a bad driver ic on the logic board, you succesfully have replaced.
just to be sure, witch card is the logic board. the one with ethernet or the one rising from the powerboard.

i have read this thread several times to figure out voltages and troubleshooting, and i think i got all the voltages right.
it sounds like i have the same problem you descibes.
it has been very interesting reading.
just need to get over the final bumb. i have to say i am noob at electronics. i am a electrician, so i hope i have a little understanding.
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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.
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@gruv2ths Ahhh you finally fixed that! How did you determine that IC was bad? Thats a tough nut to find is bad!
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Hey old friend!
It was one Hail Mary after another.
I noticed that when it was failing the preamp chip was never being un-muted. I followed the mute line from the pre-amp chip up through the riser card to that driver chip on the logic card. I pulled the datasheet and found that that pin was an output and its output was stuck at 100 ohms or something like that. The other outputs on that chip were fairly high resistance. Learned a lot, many months of four letter words though. Lol
Hi guys,
Im in need of help with my zp120 ive been following this forum, built a dim bulb tester, found a short replaced the bridge rectifier and fuse, also found a small burn mark under the tranformer one of the copper wires came off so soldered it back into place, still no power, im getting no voltage on the secondary side.
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Sounds like you have a open winding. Take off the transformer, you will probably see a burn mark where it came open.
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Also do you see 300ish volts on one pin of the transformer and neutral on another, both on the primary side?
There is also a 100 or 10 ohm 2W-ish axel leaded resistor in series with the primary, make sure that is not open.
Hi,
Ive removed the tranformer with great difficulty one of the copper pads lifted but should be ok, I also changed the resistor aswell, the only thing im uncertain of where it is burnt I cant find the trace for where that pin connects to on the board(directly above D16016) I cant see any trace or cant find hear any beep to which component its in series with.
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D16016 Cathode connects on a inner layer to the junction between C16034 and D16015. Just ohm it out, its prob fine.
That is the primary side snubber. I would also check to make sure all 3 of the diodes in that area are all ok. I have had shorts there.
Did you find something blown open on the transformer? That mark on the top side suggests an open where the pin meets the magnetic wire.
Hi,
Ive checked the transformer seems ok no open windings, is there any other checks i can do on tranformer before putting it back, also a diode d16010 reads open but when removed its ok i removed the resistor next to it and it no longer shows open, the resistance value shows fine on the DM it does show completely open in diode open is that correct.
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Well d16010 would not make it not work at all. It is the rectifier for the 15V rail I believe. If you haven't confirmed, I would check Vpri and Vmid with reference to Pgnd. If you are getting around 150V and 300V you are good, I would also pull the datasheet for the PWM U16002 (KA5M0265R ) and and make sure that you are getting the Drain voltage and primary ground on the input pins. If you are getting them both, you outta replace the PWM.
I checked VPRI and VMID and im getting 150v and 300v on them, I checked the voltage on the pwm and im getitng voltage 326v on the drain and 13v on vcc and 0.5 on fb. Im not getting the 15.4 and the 8.4 on the secondary side any ideas?
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The opto may be toasty.
The opto is the 4 pin ic that crosses the white boundary of isolation. The LED aside should read about a volt or so in slide mode, the bjt side should read a open. Do this testing with no power applied. I am pretty sure it’s the part circled in yellow. Pull the datasheet.
I tested the opto not sure if i did it right I used two DMs and connected them at the same time, there was no continuity at all when tested in diode mode on pins 3and 4 either way.
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No need to test both sides at the same time. In fact don't. I noticed that I had typos. Sorry
Just check one side at a time. LED side in diode mode, positive probe to the anode, negative probe to the cathode. Should be approximately 1V. Reversing the probes should be a open. On the output side of the opto, in continuity mode, positive probe to collector and negative to emitter, then reverse the probes and do the same.
You should get relatively high resistance (>1k ohm) in both directions. If both tests look good, then we have a good opto and the PWM is bad.

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