Author Options:

I need your help with a computer speaker amp

Hey guys, I need your help with troubleshooting a problem that I have with a pair of amped speakers that I purchased at a yard sale ($1.00!).

They are Koss SX50 computer speakers, and when I turn the switch to turn the amp on; everything goes dead. There are two speakers; each powered by 2 C-Cell batteries. This is how they were powered when they were in their Koss enclosure. I disassembled them to get rid of the ugly case.

Now, this morning instead of using a coin cell, I connected two C-cells to the speakers. This gave a little bit of sound to the left speaker. However, as soon as I hit the amp switch to on - all the sound turned off.

Here is a link to my gallery of photos of the circuit - I do not have in the picture the second speaker with the other 3V source: http://img132.imageshack.us/gal.php?g=img2265c.jpg

In the picture you will see the two-female jacks that connect to the other speaker.

I tested each speaker with the batteries hooked up and I don't get any reading of voltage. This is with the amp turned on and off.

Thanks folks


5 Replies

lemonie (author)2009-08-11

I got tired of waiting for the images to download - either imageshack sucks or those are massive files?

I don't understand how the sound turns off when you turn the amp on? Does this make a noise when it's switched off?!

"Coin cell" worries me a bit, but are you sure the C-cells are good?


Brennn10 (author)lemonie2009-08-11

Basically what I am saying is; when I hit the switch for the amp, all the previous music that was playing without the amp shorts out. The C-Cells are brand new as well.

lemonie (author)Brennn102009-08-11

So the audio feed runs the speakers (through amp board) but the amp it's self doesn't work. If the the amp was part of the 1$ yard sale buy - at a guess it's defective / totally dysfunctional? (I waited 2 min for the pic to download this time)


Brennn10 (author)lemonie2009-08-11

Yup; that is probably what I suspected. I'll probably just try checking for continuity; and where the current from the battery stops.

lemonie (author)Brennn102009-08-11

You could check the cap's - "replace cap's" is a standard piece of advice (whether it's entirely appropriate in all cases or not...) L