ms275 ko...

[stefano7689]

hello my name is Stefano, I'm from Genoa, Italy.
I inherited a phenix gold ms275 white version, namely rev-h.
The amplifier was wonderful on medium to high frequencies.
One day, while driving, following an off something must have happened, a short circuit I suppose, and he stopped playing.
open the amplifier I found this scene.


hello my name is Stefano, I'm from Genoa, Italy.
I inherited a phenix gold ms275 white version, namely rev-h.
The amplifier was wonderful on medium to high frequencies.
One day, while driving, following an off something must have happened, a short circuit I suppose, and he stopped playing.
open the amplifier I found this scene.

http://imageshack.us/photo/my-images/21 ... 25426.jpg/
http://imageshack.us/photo/my-images/90 ... 25433.jpg/
http://imageshack.us/photo/my-images/25 ... 25958.jpg/

three of mosfet irfp044 exploded!
now I would absolutely fix it, I brought a friend who fixes amps, and asked me to find the wiring diagram.
you can give me a hand?
where can be the problem in your opinion?
regards Stefano

[zeropoint0.5]

try to upload pics again, you can only see red crosses........

[stefano7689]

Here are the photos! Does anyone know what is the switch on the motherboard?

[zeropoint0.5]

the switch lowers the rail voltage so you could play on lower impedances if i'm not mistaking....

It seems you have here blown up you're powersupply....... but it will normally be possible to repair it......

[trickyricky]

Might as well replace the caps. Don't forget the gate resistors for those fets, they might be off a bit or damaged. Also check the outputs before powering up. Its repairable, but the components may not be cheap, but the amp is worth it.......just look at that sexy board.

[valeks1]

The reverse polarity diode is blown. This only happens when the B+ and B- wires are connected to the amplifier backwards. This can also damage your PS MOSFET’s and this is why they blowup.

[stefano7689]

What do you recommend I do? replace the diode and the mosfet? and that's it?
the circuit diagram does not have any?

I have not reversed the polarity! the amp sounded! it may be a short circuit?