After replacing some switching transistors and IC chip, I was using a 19v laptop pwr supply as the DC input. To my surprise, when I switched to a 12v supply the inverter came to life! Apparently the higher input voltage from the 19v laptop pwr supply shut down circuitry, preventing the inverter from powering up until I switched to a lower voltage supply. I may have used one too many parts but am sure one of four switching transistors was shorted.
fdryer, July 2009
