U1 looks to be an audio output module (assuming that grey area to the left of it is an attached heat sink). Positive feedback would make it oscillate. Is there a part number printed on it?
No, wait. That's a capacitor, not a heat sink. Still, I think the IC is an amplifier of some sort, configured to oscillate.
The black thing in the upper-left-hand-corner would be an inductor in parallel (or possibly series) with one of the capacitors, creating a resonant circuit that determines the frequency of oscillation.