This phenomenon still belongs to the switch power supply itself or its load caused by short circuit fault, the line circuit disconnect, then plug in dummy load (60 w / 220 v bulbs) boot test, measuring line output tube collector voltage of 250 v (normal should be 110 v), other groups of output voltage. When off operation output transformer (4) feet after the false, the output of the load and electrical measuring pipe c voltage is 250 v, when connected to the load output voltage (4) feet quickly to around 40 v, then disappear to 0 v concluded that partial short circuit line output transformer, with the same model line output transformer after, all is well. dpQservice manual download site
 dpQservice manual download site
 dpQservice manual download site
Note: this kind of failure are common, the aircraft used line output transformer damage rate is higher, and the phenomenon of the show is almost the same.dpQservice manual download site