"poorly designed, with the live connection far too close to an energy-monitoring chip," according to Which? "This could cause an arc – a luminous electrical discharge between two electrodes – which poses a fire risk, particularly to older homes with older wiring."
In the electrical engineering world, PCBs with issues like this are like hard-coded administrative passwords in the software world. All too common, an easy mistake for a total novice, an obvious blunder for someone with experience. If you see that issue, it's a big clue that other important factors were missed, and you should do some more digging.
Even the cheapest PCB layout tools have automated design rule checks that can catch these.
Biting the hand that feeds IT
