What was found
(CAN) ON INIT POWER-UP OF SOME UNITS, Q306 IS FAILING RESULTING IN INABILITY TO DIM CVR FAIL, FDR FAIL, & PASS ANNUNCIATOR LAMPS ON CVR CNTL PANEL. A NO OF UNITS HAVE BEEN RETURNED FROM SERVICE WITHQ306 FAILED. TESTS AT NAT HAVE CONFIRMED THAT SIMULTANEOUS APPLICATION OF 28VDC POWER TO UNIT POWER SUPPLY & LAMP DIMMING SUPLY CAUSES EXCESSIVE CURRENT THROUGH BASE-EMITTOR JUNCTIONOF Q306 WHICH CAUSES IT TO FAIL. THIS CONDITION IS CAUSED BY A DELAY IN INTERNAL POWER SUPPLY PROTECTION CCT.