Repair ZP120

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… 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.

I finally got back to this -- checked all the DC voltages and they all match your reference. Even with my fluke truerms I didn't validate the secondary but I am guessing I referenced to the wrong point. The DC busses all look OK.

I am thinking to pop off the shield can on the logic board to get at the UART. Any other thoughts? Still a solid white LED.
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 [immr=0x0d10,k=0x00e1]) at 300 MHz
Board: Sonos Wembley
DRAM test
Test complete - 1 errors, error pattern 00400000
### ERROR ### Please RESET the board ###
I went ahead and ordered 2 2DRAM parts since I don't know which is bad. Anyone tried this replacement? I might have to remove the shield. If not I'll remove the parts with hot air and then put the new ones down.
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Never done this. Looking forward to your results!
Never done this. Looking forward to your results!

Well, I was able to change the DRAM out without much issue. I used kapton, some foil, and the hakko hot air rework. Then I cleaned the pads and put new parts down. Unfortunately, it did not fix it. That pretty much confirms that the issue is probably a cracked solder ball under the BGA, or head-in-pillow or some other similar type defect. I thought about putting it in the xray but it is so hard to see some of these defects and regardless of what I found, it was not repairable.
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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?
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.
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Figured this would be a good thread to piggyback onto.

Anyone have a zp120 parts unit they want to sell?
I have a unit with a bad top board (must have gotten hit from lightening on the ethernet.)
Almost every component I pull is shorted.

I do have a good power/amp board if I cant find a controller/wifi board to marry it.

I've got an Connect:Amp that I bought for parts and trying to repair. 10 Ohm resistor totally burned up and charged the board. Replaced that, the fuse, the PWM and a cap that was puffing at the top. I've got voltage on the PWM but nothing on the secondary side at all. I've pulled D16016 and it gives me continuity in both directions so first this is to replace that. Does anyone know the specs on this diode? 15V, 3A? What about the package type? Just need to order some from digikey.

Also, my CPU_GND and 36V GND test points are not buzzing out as shorted. Does this indicate there are other components blown on that side of the transformer? I get no voltages on that side of the transformer BUT I am using a crappy craftsman DMM that probably doesn't work for reading the fast switching voltages on this board.

Any help would be appreciated!

I have a Connect that forgets its configuration. It worked on ethernet but when it was moved to a location that required wifi, it just wouldn't stay connected. After that, it wouldn't stay configured on ethernet either. Sonos made a ridiculous repair offer. For another $60 I could buy a new one. Anyway, does this sound like a logic board problem? I'm thinking on buying a parts unit to see if I can get it working. Any thoughts?
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Hey Dan (danrowland),
Can you tell me more about that diode. I dont know them by refdes, more by function.
The CPU_GND and 36V GND are supposed to be tied together, in fact they often blow open and then the biases are not referenced to each other and nothing works.

So if you replaced the PWM and the 10 ohm, then are you getting high voltage on the PWM drain pin?
You should be getting 300ish V across the 2 big storage caps on the primary side. (if I remember correct). If you are not then you still have problems in the rectifier and storage section just before the bias PWM.

There is also an opto in the bias converter feedback that can blow, also the bias converters bias winding storage cap that can cause it to not work.

Hope this helps.