Neumann KH120 studio monitor power supply repair

[MattLuie]

I repaired many power supply in the KH120 the problem was the four 220uF25Vdc capacitor around the two regulator in the output, psu, if the primary can start you can try that, I worked for Sennheiser-Neuman for a long time, good luck

I really appreciate you for sharing your experience here it definitely helps us
Thanks again

 

[MattLuie]

Hi again Folks
I'm here to report new updates
Last night I received new MOSFET which is 11N80C3 by infineon and I replaced it
But this time MOSFET didn't short very fast it shorted after 1 or 1and half min...
Really I'm going crazy this device isn't repair friendly guy's
Does anyone knows what value is the diode after this optocoupler that I attached down here
The diode was damaged I replaced with new 4148 MiniMelf I guess I made a mistake......
Best regards

 

[MattLuie]

I repaired many power supply in the KH120 the problem was the four 220uF25Vdc capacitor around the two regulator in the output, psu, if the primary can start you can try that, I worked for Sennheiser-Neuman for a long time, good luck

Sorry for asking but do you have any schematic of Neumann speakers????
I really need it to understand what's going on with these speakers....