For what it is worth, on mine there are two switching regulators(boost) each operating off their own Richtek RT8462GS, which are in a 14 pin package. You will see two identical circuits on the pcb. I Ramp up the Voltage (lab supply) and it was obvious which devices were getting hot, so I unsoldered those and the other regulator started working and LED's turned on. Shotgunned the failed circuit and replaced the FET, Richtek PWM, boost diode and an LDO ... maybe $10 in total off digikey and was back in business. The real hassle is that the PCB is conformal coated, so that has to be scraped off. The parts are SMT, so you'll need to be able to deal with that. If your failure is similar, I can probably track down the other parts I used. Kessil would not tell me the part numbers, and the small SMT's markings are difficult to read.