Fisher Intergrated Power amp CA-270.

Yesterday the left channel and speakers went out.
This occured after the speaker selector was changed to a position where no
speakers were attached.. Could the lack of resistence have caused this?
This is a 20 year old unit that sounded great.
There are 3 speakers in the cabinet,how do I check if any are still good.Do
I check for resistence at the speaker cabinet connectors?
Also what do I troubleshoot at the amp.
It does not pay to send it out for repair and I am trying to save it.


Thank You

"DanFXR" wrote in message
...
Fisher Intergrated Power amp CA-270.

Yesterday the left channel and speakers went out.
This occured after the speaker selector was changed to a position where no
speakers were attached.. Could the lack of resistence have caused this?
This is a 20 year old unit that sounded great.
There are 3 speakers in the cabinet,how do I check if any are still
good.Do I check for resistence at the speaker cabinet connectors?
Also what do I troubleshoot at the amp.
It does not pay to send it out for repair and I am trying to save it.


Thank You

A semiconductor amp should not care about lack of load. Driving it into an
open circuit should not cause damage. On the other hand, driving it into too
low an impedance, is an issue. If you have been fidling with the speaker
connections and impedance selection, you may have inadvertently whacked a
short across it. If you are lucky, it might have just knocked out an output
fuse. Many amps from 20 years ago had fuses in this position. Sadly modern
ones don't.

Check first for blown fuses, and if you find any, make sure that you replace
with like for like ie not just the fusing rating, but also the type, F or T.
As far as the speakers go, an easy way to do at least a basic electrical
check is to just connect a 1.5 v dry cell across each one in turn, both ways
round. The cone should move forwards and backwards by an even amount, and
produce a nice clean thump sound. Alternatively, use a multimeter on its low
ohms range. On this range, it will supply enough current to the speaker, to
hear a thump.

Arfa