On Sun, 26 Feb 2017 11:51:57 +0100, Sjouke Burry
wrote:

What is most weird, there is a LED on the board which says "LED" and the
caps have numbers next to them (in english).

I plan to contact the seller to ask for an email containing the
schematic or a photo showing what is what.....

This is the first time I have ever run across a PCB labeled in
chinese...



Get the ground connection with your ohm meter on each block.
Attach a small speaker to each terminal block, if your print
is mono.
If stereo, use two 20 ohm resistors to connect the other side of
the speaker to the l/r in/out points.

Connect power.

Then tap on the speakers, and the outgoing one will
echo that, with the one on the input acting as microphone.

Keep the speakers away from each other, or you will have a siren.

Thanks for everyone's advice. I solved the problem by looking on Ebay.
The seller I bought this from does not have the diagram, but there are
several other sellers selling this same amp. Several of the other
sellers have a photo of the amp, with pictures of speakers and what they
connect to. (Including which screws are + and -).

There are 3 screw type connectors. One is the 12VDC power, the other two
are speakers (L and R). The 1/8" jack is the input for a STEREO plug,
such as the SPKR jacks on the back of a computer.

I plan to tell the seller I bought this from, to please include that
diagram on his ad. (I saved a copy of the picture for future reference).