[u235vu239]

I bought this pioneer amplifier (SA-408, similar to the SA-410, I guess), but it has two big problems:

1. when I turn up or down the volume, it makes this really nasty noise

2. it seems that it can't reproduce the left channel, as the whole "RCA lefts" seem to be dead (only the "RCA rights" can reproduce any sound)


Can someone tell me what I can do?
Thanks in advanced

u235vu239 wrote:

I bought this pioneer amplifier (SA-408, similar to the SA-410, I
guess), but it has two big problems:

1. when I turn up or down the volume, it makes this really nasty noise

Dirty potentiometer. Often you can get the dirt out by just turning it
back and forth over it's working range ten or twenty times. If that
doesn't work use a contact cleaner, or replace the pot.


2. it seems that it can't reproduce the left channel, as the whole "RCA
lefts" seem to be dead (only the "RCA rights" can reproduce any sound)

A dirty switch can cause this, especially the tape monitor button. Or
you might have something actually broken in the signal path. Hard to
tell from here.

//Walt

[u235vu239]

Originally Posted by Walt

u235vu239 wrote:
[color=blue]

A dirty switch can cause this, especially the tape monitor button. Or
you might have something actually broken in the signal path. Hard to
tell from here.

//Walt

How can I clean the tape monitor button? And could it be any other button?The signal path seems to be ok, but if there's something broken, can it be fixed?


Thanks a lot, I really appreciate your help

[u235vu239]

Originally Posted by Walt

u235vu239 wrote:

I bought this pioneer amplifier (SA-408, similar to the SA-410, I
guess), but it has two big problems:

1. when I turn up or down the volume, it makes this really nasty noise

Dirty potentiometer. Often you can get the dirt out by just turning it
back and forth over it's working range ten or twenty times. If that
doesn't work use a contact cleaner, or replace the pot.


2. it seems that it can't reproduce the left channel, as the whole "RCA
lefts" seem to be dead (only the "RCA rights" can reproduce any sound)

A dirty switch can cause this, especially the tape monitor button. Or
you might have something actually broken in the signal path. Hard to
tell from here.

//Walt

By the way, it's a transistor amplifier. Could it be a ruined transistor?

u235vu239 wrote:
How can I clean the tape monitor button? And could it be any other
button?The signal path seems to be ok, but if there's something broken,
can it be fixed?

Anything that isn't buried inside a chip *can* be fixed, and chips can
be replaced... the question is hassle and cost.

Start by working your way through the signal path to find the problem,
then decide what to do about it.

Though if you need to ask, odds are you'd be better off getting someone
else to deal with it...