fisher 70AZ

[maciek]

got this mono fisher 70AZ amp,after cleaning hooked it up,men played so nice,but after while started hearing strange sound and can cap started getting hot,turned it off ,inside chassis found brownish jelly leaking,guess it went bad ,should it be replaced or else,anybody has schematic of fisher 70AZ,thanks for help

[HollowState]

Originally Posted by maciek

...but after while started hearing strange sound and can cap started getting hot,turned it off ,inside chassis found brownish jelly leaking...

Yup, that's because you made the mistake of powering up an old amplifier that probably hasn't been used in a long time without bringing it up slowly. So the tired old capacitor couldn't take it, ran hot and spilled it's guts. It's bad now and will have to be replaced. But it's not a big deal and something that a little money and effort won't fix. You don't need a schematic. The capacitor values are marked on the side of the can. If it has a cardboard covering, remove that and the values should be underneath. New caps are available from several dealers on line.

[maciek]

i belive that is what exactly happend,it is aluminium can cap ,should it be stuffed with cas values wrtitten on it,how they get connected all together,

[maciek]

thanks

[Tom Bavis]

The cans can be restuffed - modern caps will fit inside. But it's easier to put separate caps underneath - add a terminal strip. One trick is to mount the terminal strip by soldering it to a terminal on the can cap - no holes required. Be sure to connect the negative leads to the same spot as the original can.

Schematic is in Sams folder 263-8 - I found a copy online by Googling "Fisher 70A schematic". The AZ adds some components in feedback look - otherwise same as 70A.

[maciek]

Tom,thanks for advice,let you know how i did,