Repairing a Yamaha keyboard

So my family's keyboard had a few keys that didn't make sound when pressed. It is not a good keyboard in the first place (though it did accompany me or mostly my bro to various performances and competitions) and very old (>10 years), so I didn't want to repair it. But my mom was asking me to.

So on a free day, I took it apart to try my luck.

All the screws that are visible from the bottom need to be removed. Including a few long ones nearer to the center hidden in rectangular holes. The battery compartment cover also needed to be removed for some reason.

For you electronics porn lovers out there. That includes me.

The speaker. Doesn't look half bad.

The amp chip - an LA4705

The board.

What caused the malfunction was the large grey ribbon cable. It was probably rusted and broken inside. Because repositioning it solved the problem.

Time spent: 15 minutes