My brother has got a Bosch cordless lawnmower that uses 36V battery packs. He presented me with the charger, which was completely dead – no LEDs lit at all when plugged in, and nothing on the output terminals. Checking the circuit board, there was nothing visibly wrong, so it was time to hit Google. I found an old post on a Polish forum that suggested that a 180k‎Ω resistor fails. The resistor looked fine, but after desoldering it, it measured open circuit.