Repair ZP120


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

Has anyone taken one apart?

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Ok thanks for your fast reply, I indeed looked at the posts before and saw the scheme of all the readings at the pins. I thought I could not test this because when I power on the device it blows up. I will build a dim light tester, check the transformer and the pwm again as well as the diodes. I have a very cheap multimeter with a diode function, is this trustworthy?

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Ok thanks for your fast reply, I indeed looked at the posts before and saw the scheme of all the readings at the pins. I thought I could not test this because when I power on the device it blows up. I will build a dim light tester, check the transformer and the pwm again as well as the diodes. I have a very cheap multimeter with a diode function, is this trustworthy?

Yes even a cheap diode tester should work.

 

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readings at the pins. I thought I could not test this because when I power on the device it blows up. I 

I have an educated guess about what is wrong with your device.  If you replaced the PWM and it still doesn’t work, then I’d check the two mosfet devices identified in these images.  Look for a short between the various pairs of pins (you should not find any 0V drops if you test the 6 combinations with a diode tester).  If you don’t have a diode tester, you can just remove the 2 components and see if the device boots up. 

These devices are part of the circuit that is used to generate 36V power that is used to drive the amplifier.  It is only active when the device is actually playing music.  An otherwise working device will boot up without them, and will even play at very low volume.  After booting up without the 36V present, you won’t be able to turn up the volume, and the device will start flashing amber.  This isn’t permanent and it will go away once you replace the mosfets.

When the time comes, be aware that the silver clip on the top can be a pain to replace.  It can be bent open with two sets of pliers so that it is just a bit narrower than the diodes it covers.  That will let it do its job and it will be much easier to replace.

 

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I forgot to attach images to my previous message.  Here they are… the mosfets are marked in red boxes.

ZP120 underside - MOSFETs marked with red box
ZP120 internal - MOSFETS marked with red box

 

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Hello, im from Germany and need your Help.

These two capacitors are defective. do you know the data for these?

TH16001 and TH16002.

 

Thank You

Max

Hi there, are these thermistors the same as they are in an playbar? In my playbar, the green thermistor are burned and I´m looking for the type.

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TH16001 and TH16002.

Hi there, are these thermistors the same as they are in an playbar? In my playbar, the green thermistor are burned and I´m looking for the type.

SCK-054 or SCK-083 will work.  These limit inrush current, and either of these does that (they have 5 and 8 ohms of initial resistance).  The maximum amperage is 4A for the SCK-053, and 3A for SCK-083.  Either of these is more than enough current for a playpar.

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Do you mean a SCK-054 or a SCK-053 with 4A? Anwalt,here in germany, I don't find anyone,  who sells one of them. 

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Do you mean a SCK-054 or a SCK-053 with 4A? Anwalt,here in germany, I don't find anyone,  who sells one of them. 

I meant SCK-083.  Here is a datasheet for the series… https://datasheetspdf.com/pdf-file/924750/Microtherm/SCK-054/1.  Looks like an SCK-103 will work too.

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But sure… if you can find an SCK-053 (another manufacturer perhaps), then that would work.  I think you want the first two digits >=5 and the last digit 3 or higher.

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I'm sorry, but I'm going to be stupid trying to find a suitable spare part.Can someone give me a link to a suitable spare part, e.g. at mouser or digikey?Many Thanks

readings at the pins. I thought I could not test this because when I power on the device it blows up. I 

I have an educated guess about what is wrong with your device.  If you replaced the PWM and it still doesn’t work, then I’d check the two mosfet devices identified in these images.  Look for a short between the various pairs of pins (you should not find any 0V drops if you test the 6 combinations with a diode tester).  If you don’t have a diode tester, you can just remove the 2 components and see if the device boots up. 

These devices are part of the circuit that is used to generate 36V power that is used to drive the amplifier.  It is only active when the device is actually playing music.  An otherwise working device will boot up without them, and will even play at very low volume.  After booting up without the 36V present, you won’t be able to turn up the volume, and the device will start flashing amber.  This isn’t permanent and it will go away once you replace the mosfets.

When the time comes, be aware that the silver clip on the top can be a pain to replace.  It can be bent open with two sets of pliers so that it is just a bit narrower than the diodes it covers.  That will let it do its job and it will be much easier to replace.

 

thanks! I found a short on the mosfet side, but to be sure, I also want to replace the schottky diodes on the other side… Do you have any idea on what replacement part to order for these? 

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I'm sorry, but I'm going to be stupid trying to find a suitable spare part.Can someone give me a link to a suitable spare part, e.g. at mouser or digikey?Many Thanks

Either of these will work (both are in stock as of now)

Mouser #: 527-RL4504-3.2859S54

Mouser # 954-5D2-10LD

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thanks! I found a short on the mosfet side, but to be sure, I also want to replace the schottky diodes on the other side… Do you have any idea on what replacement part to order for these? 

If you are referring to the pair of TO220 Schottkys mounted to the case, those are 10 Amp 100 Volt.  Part number SBR1010CT

 

Hello, im from Germany and need your Help.

These two capacitors are defective. do you know the data for these?

TH16001 and TH16002.

 

Thank You

Max

Hi guys, I own a connect amp that was plugged (by previous owner) in to 220v when switch was on 110 v.

I replaced the fuse, replaced the TVR14241 (mov) and i noticed that the TH16001 also cracked. I could not source the Sck054 needed to replace this part in my local electronics store, so I hardwired it for now, and everything works perfectly. 

Questions are:

- with normal use (no power surge, no wrong voltage), will the unit get damaged if I keep it like that? 

- is th16001 used in 220v setup, or is it for 110v only, and th16002 for 220v?

 

If it will Increase the lifespan of the unit, i will order the SCk054 online.

 

Thanks for this super interesting group discussion, got me already quite far!

thanks! I found a short on the mosfet side, but to be sure, I also want to replace the schottky diodes on the other side… Do you have any idea on what replacement part to order for these? 

If you are referring to the pair of TO220 Schottkys mounted to the case, those are 10 Amp 100 Volt.  Part number SBR1010CT

 

the short I mentioned was not correctly diagnosed. So No short is detected on the mosfet side. Schottky diodes also seemed ok after removing them.
 

I build a dim light bulb tester, replaced the 10 ohm resistor, and removed the MOSFET’s and schottky diodes. When plugging the device in, the bulb goes full brightness. I am using a 53W bulb. Also plugged it in With the input/network card removed. Lamp still goes on… Owner told me the damage was probably caused by water as the amp was placed under a bathtub… Any thoughs? Not sure If the PWM is still ok But as I replaced it last month, it should be.

I have noticed that the 4 diodes (marked with black stripe) do not give any Reading on my multimeter.

 

Update: removed almost all diodes from underside op primary side. Theyre all Good. Something I noticed is that all the 5 points of this winding in the secondary side are shorted together, is this right? 

 

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Hello, im from Germany and need your Help.

These two capacitors are defective. do you know the data for these?

TH16001 and TH16002.

 

Thank You

Max

Hi guys, I own a connect amp that was plugged (by previous owner) in to 220v when switch was on 110 v.

I replaced the fuse, replaced the TVR14241 (mov) and i noticed that the TH16001 also cracked. I could not source the Sck054 needed to replace this part in my local electronics store, so I hardwired it for now, and everything works perfectly. 

Questions are:

- with normal use (no power surge, no wrong voltage), will the unit get damaged if I keep it like that? 

- is th16001 used in 220v setup, or is it for 110v only, and th16002 for 220v?

 

If it will Increase the lifespan of the unit, i will order the SCk054 online.

 

Thanks for this super interesting group discussion, got me already quite far!

The thermistors here are NTC (negative temperature co-efficient).  These will have a higher resistance when cold than once they warm up.  I’m not an expert but I think that the purpose is to limit the inrush current when the device is first plugged in.  These are used in most sonos devices that drive speakers.  Each of these has large capacitors that charge up, and which will draw large amounts of current quickly without the thermistors.  You may notice your lights dim a bit when you plug in a device without them.  I notice this dimming with the ZP120 Connect:AMP devices, and that’s with the thermistors working!

The thermistors are active in both 110v and 220v devices.

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Update: removed almost all diodes from underside op primary side. Theyre all Good. Something I noticed is that all the 5 points of this winding in the secondary side are shorted together, is this right? 

 

The secondary winding has two separate coils.  The first is across three pins with a centre tap.  Within each coil (the first 3, or the second two pins), you should measure a very tiny resistance (under 1 ohm) between the pins -- this is normal for a transformer.  The short between the two coils is not normal.  You may have a short between the two secondary coils, or it could be ‘downstream’ of that.

I’ve fixed dozens of these devices and haven’t seen this particular problem before.  You can try to remove the transformer and see if the dim bulb stays bright.  If it does then the transformer is probably not the problem.  Be warned though… Getting that transformer out and then re-installed is a pain to do.

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