[Closed] Electronics help

My wife's sewing machine has these little white LEDs to illuminate the work area. They starte flickering, like regularly about 10Hz or so, not a 50Hz flicker.

They are attached to a little PCB containing a resistor and a bridge rectifier IC. What's likely to be failing? The IC, the LEDs? Or something else?

Thinking about it - would seem unlikely that both LEDs would fail at the same time and flicker in the same way - so it's either the IC or the power supply.. How do IC rectifiers fail?