Identifying a MIDI board

Dear Arduino forum,

I recently took apart my old MIDI keyboard, and I found the board that is in the attached pics. I am looking to build a MIDI instrument with it, but I can't identify the board and so I don't have a datasheet. I don't know what ports give what signal etc. Could you help me either identifying this board or give me guidance on how to find out what does what? Thanks a lot in advance!

PS: I can post additional pictures of certain parts if that is needed.

IMG_0382[1].JPG|2592x1936

Start at the USB socket and trace the wires going into a big chip. That is the one that makes the computer think it is a MIDI device. I bet it will be U1, the one with lots of legs. It is probably a processor of some kind.

Thanks for the advice. I've tried doing that, but to no succes. I was thinking, maybe I could just cut the wires coming out of it, and connect those to the Arduino one by one. Then I'd send a HIGH signal over it and see what happens. Possible?