Toshiba A10 Stereo Amplifier only playing mono.

[bendib2003]

Hi.

The amp will now only play mono after the AUX cable was unplugged from the amp while music was being played from a computer. After plugging them back in, I wasn't able to get it back to stereo. I've looked around for a stereo to mono button or switch but can't find any, I've also checked that my computer is set to stereo, and it is. I know that it's not the speakers because I've swapped them around in the sockets on the right in the picture below and then the other speaker starts playing on mono. I really don't want to open it. I've thought of 2 possibilities, either the AUX cable was broken when it was removed, but this seems strange because the same speaker still plays no matter what AUX plug I pull out. The second is the socket on the very right is broken, but since it happened when the AUX was plugged out I am not sure about that. I would appreciate all the help I could get, if someone thinks there's a fix without opening up the amp I would appreciate that as well.
I've also tried putting the white AUX end into the red slot and vice versa, same speaker still plays but slightly quieter.

Here's an image of the back of the amp: imgur: the simple image sharer
Thanks in advance.

[Jazz P Bass]

Toshiba SB-A10 Service Manual

Have you tried a different input jack?

Try the Tuner In & select for it on the front panel.

If you have no sound at all from one speaker, regardless of the input jack used, then you may have a power amplifier circuit issue. (ie: blown power amp)

[bendib2003]

It still only plays on one speaker, is this power amplifier circuit issue an easy fix or fixable at all?

Edit: And what does blown power amp mean? I searched on a few pages and I got the impression that it's the "Speaker terminal" that the manual you linked calls it.

[Jazz P Bass]

The power amplifier circuit is just that.

It is the circuit that 'powers' (Voltage x Current) the speakers.

And no, it is not any 'easy' fix if you knowledge of amplifier circuits is lacking.

[oc disorder]

Hi bendib2003
What JPB is saying is when the aux got unplugged, it possible some sorta nasty spike occurred which made an internal component in one of the two power amps (Left & Right) hand in its retirement card ! This will need a suitable detective (technician) to fix even if it is just one of those 100 ohm fusible resistors.
The only other thing which I can think of that is user serviceable ie something you can try without removing the cover is this... bear with me....
A frequent problem in guitar amps is a patch point. This is where there are two sockets for a muso to insert an echo or effects device to add to the sound.

These 2 sockets or at least one of them contains a switch which opens when a plug is pushed in. It opens a pathway which makes the signal (sound in an electric form) travel up that plug through the echo or whatever and back from that into the second socket and back into the amplifier and obviously on to the speaker so it can be heard.

Now the important part of this is when the plug or plugs are pulled out the switch inside the socket that originally was forced open should now close allowing the signal to follow it's normal course. If it doesn't close because of dust or grit the electric signal can't get through.
Whats this got to do with your Toshiba ? Well it has a headphone socket that is designed to disconnect the speakers when headphones are plugged in.
It is possible as it has two switches one for the left and one for the right that one of them is not connecting.Normally this means it needs cleaning so to test out this theory you need a pair of headphones. Often firmly pushing a plug in and out of the headphone socket a few times may dislodge dust etc which would hopefully allow the switch to connect properly thus reconnecting the speaker.
So try some headphones and if they work that's the problem.. the normally closed switch in the headphone socket. The white and red can be interchanged one is the left signal and one is the right. It just means the cellos and double bases will now be on the left and the first and second violins will be on the right. Of course you will have to listen with your back to the speakers...

[bendib2003]

Sorry for not replying. Update on the issue:

The problem is now solved, I appreciate all the help but it turns out my incompetence when it comes to amps (and in this case, this particular amp) was the problem.
As soon as my dad comes home he knows the issue, and it was simply the balance control behind the volume control that was turned all the way to the left. Sorry for the inconvenience and I hope I didn't take too much of your time because of this.

Again, thanks for all the help.

[Jazz P Bass]

Live & Learn