Repair ZP120
Has anyone taken one apart?
Hi Tim, thank you. I have now ordered two of them. Can I destroy them by changing the AC voltage from 230V to 115V on the 230V grid?
Yes that could cause a lot of damage. The usual rectification generates the input times the square root of 2 as DC voltage. SO 115V input translates to about 162V. The switch on the back adds a voltage doubler to the rectifier circuitry. With a 115V input, that produces 320V internally, which drives the high voltage circuitry. If 115V is selected but the input is 230V, then it would internally generate 640V DC. That could break a lot of things. All of the power passes through the thermistors, and they blew up in protest of the voltage. The question is if they went before anything else ‘downstream’ died or not. It is possible that there was also damage to the PWM chip. This is the four pin device on a heatsink next to the transformer. You can check if it’s pins are shorted or not. If there are short circuits between pins then it is dead. If there are no shorts, it doesn’t mean that it isn’t broken though.
EDIT: Never mind, I just found the other hidden screw to the left of the sub woofer analog output. Looking around now....
@gruv2ths: Any ideas on where I should check next?
ALso, what is the voltage across these 2 pins?
Сould you please tell me the value and marking of the resistor R16021?
Do you have the gray ribbon from the front buttons to the logic board connected? (it connects under the wi/fi card)
Hi Im not tech enough to open and start fixing mine.
Could there be anyone that could fix mine?
Ive talked to Sonos, but no help there. It online and apparently “working” but no sound.
Cables and speakers working fine.
I have no idea what kind of solder that Sonos uses, but it is insane. In order to get it to melt, I had to get my Hakko iron up to 900 degrees. 700 (its default) would barely get it to melt. Getting it off components was a chore. That PWM and heat sink took a good 45 minutes to get off along with about 2 feet of desoldering braid. I am surprised I didn't destroy contacts as I really had to put that iron on for a while to get that solder to move. I tried a desoldering pen too, but to no avail. The best way to get it off was keep cracking at it with desoldering braid. I would love to hear if anyone has any hacks or ways to deal with such a problem. ...
🙂
- The solder was no doubt lead-free, which has a much higher melting temperature than lead-content solder. The solder that is touched directly by the iron will melt but due to temperature drop further away from the iron, some solid solder will remain. Use a solder sucker to get as much solder off the joint as possible. There will probably be some solder remaining in hidden areas which makes it impossible to pull the component out. The heat from the solder iron does not get conducted to those hidden remnants of lead-free solder; so add some leaded solder* to the joint and let it flow in. The leaded solder will mix with the lead free solder and alter the alloy to lower the melting temperature. The added solder provides a better heat conduction path. Suck it clean again. Repeat a few times if needed.
Apply the iron to the component lead, not to the pcb pad. The copper clad of the pc board will peel away from the fiberglass if it get heated too much.
*Rosin core solder can get messy, and the rosin flux is not really needed since the copper has already been tinned. Find a spool of lead solder without a flux filled center in the plumbing department.
The board does appear to be getting power as some of the small resistors around the burned one are getting voltage readings.
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.
@gruv2ths: Could you possibly take a picture of this circuit on your amp and post it here? The reason being is I am assuming the burned resistor values are the same as the other side (750 = 75 ohms) but I want to make sure. Also if you have any advice for me I would much appreciate it as I am bit rusty when it comes to component level troubleshooting.
Thanks,
Andy
ok-that what interesting, after I thought I had removed the short from the inductor I soldered it back in mounted on the bottom for evaluation, I had a pigtail 5 amp fuse and brought it up slowly with my variac and the 5 amp fuse blew. I thought I was getting a very high resistance reading between the 2 windings where there should be none, I ended up fully unwrapping the inductor and rewrapping it, put a current meter in place of a the fuse in and slowly brought the variac voltage up,watching the current draw, stayed low and got the white light on front and made it up to full voltage with no issue...now to put the inductor back in correctly and try to connect...looking real good!
If you take a pic we may be able to tell you the values of the components that you need.
Did you double check that inductor and does it have a number on it? The bad news is that inductors can be difficult to track down as many are custom. The good news is it really takes a lot for inductors to blow. So hopefully it’s not bad. One of mine had burn marks on it but still ran like a champ. If it has numbers then we may be able to find it. Pictures will help. I noticed for myself that getting my phone close allowed me to get s better look at the numbers.
I read a lot of things but my English is limited, so I will explain my problem.
I have a ZP100 that works from 3 to 40 minutes when it is turned on, then there is more music and it disappears from the application ....
The problem is already may have happened to one of you, and if so how to solve it?
Thank you very much.
Thanks,
Andy
Also... If those are the 1000uf big caps, that are in that picture... they normally have plastic caps on them to prevent the board from causing a short. I would recommend putting the plastic caps back on them or place some electrical tape over them to shield them from touching the board.
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