Chicco Keyboard fix

Chicco Keyboard Fix

I don't know how to pronounce the name of this toy keyboard, and I don't know who made it. What I do know is that yesterday it wasn't working.

The power LED came on when switched on, and an odd squeak was heard when some of the buttons were pressed, now and again it would burst into life, then just stop. New batteries didn't fix the problem.

Off to the workshop, then, and I took it apart and expected the dreaded battery corrosion but no, it was fine inside.. Inside there is a power amplifier (JRC386D) 

JRC386D

and what must be the main IC mounted on a daughter board. It's a die under a black blob thingy, so no idea what it is.

There was nothing obvious wrong so I was about to get the scope attached and see what was going on when I noticed that if I touched the daughter board then the speaker crackled. i had a look at the soldered joints and they did seem to have a crack, so I re-soldered them all. That seems to have fixed the problem, the little keyboard makes lots of noise again.

https://youtu.be/IJ18SS9MJtU