Hey....hery world. I have a problem with One of our new, OH prop ( No 2 posn)which is fail to pitch lock. Synchrophaser operation ck, slave follow both 2 and 3 master, RPM goes upto 104.5% fuel flow also 1400-1350 but rpm does not reduce like no 3 prop which is pitch lock SAT with the throttle movement with check switch is actuated. Low pitch stop adjusted, pitch lock regulator replaced, no joy. TD controlling unsat. Any suggestion.