Main circuit board for yesterday's shredder. Fault wasn't here, but was just the switch for the front panel Off/On button. Suspect some dust had found it's way in there. Applying a little switch cleaning lubricant, working the switch with the power off*, and then allowing the solvent to evaporate*, seemed to sort it.

* Vitally important... if you'd prefer to avoid a fireball! A teeny spark at the switch contacts can easily ignite the highly flammable solvent present, as I once witnessed when a too hasty colleague switched on a hairdryer straight after applying a liberal dose of switch or contact cleaner. He retained his eyebrows, but only just! He immediately turned off the hairdryer, but I suggested that he could now turn it on relatively safely, as he'd burnt off all the solvent without setting anything else alight. It then worked okay.