X-5 shorted center channel

[ROLIKOV]

Hi
I have the X-5 five channels amp. which is awesome ,
But unfortunately , today i made a stupid mistake , i made a short circuit to the center channel , and now the sound is hoarse .
I have the service manual ,
Need some advise of how repair this baby ,
I am going to start check the 4 pairs of Mosfets of the center channel , and i will be happy to receive some tips

Thanks
ROLI

 

[h_a]

I assume you shorted while playing music, right? Without signal not much should happen.

Check as you already said the output fets, by testing bias currents and such.

Be aware that the service manual does not state the correct voltage across the source resistors; in fact biasing is not exactly known for the X5. You could contact Nelson for that.

As the X5 has a common toroid and no regulation for the output stage I guess only the output fets should be affected.

Have fun, Hannes

 

[Nelson Pass]

Most of the time you need to replace the Mosfets, the Source resistors, and
the zener protection diodes in any pair where one or the two are damaged.