Matt silent after switch on the machine, the machine has "squeak" sound, but sometimes the cold boot can work normally in a short time. Sometimes can work normally in a short time, analysis is variation caused by the device performance. For failure occurs when the measured + B113V normal, while measuring R536, R519 voltage of 1.1 V, normal is about 8.5 V to 9.0 V. Protection circuit has action and protection. Release R536 (56 Ω) short of commissioning, images, audio, all normal, did not find over-voltage or high voltage testing related key phenomenon; Repeated commissioning and to extend the time of watching, no exception happens, analysis is likely to be resulted from abnormal protection circuit itself protection misoperation. Q451 in road detection protection circuit, Q., 503, positive and negative to the resistance value Q504 are normal, with digital meter check delicate C452, C507, C580, C256 electrolytic capacitor, such as found C580 100 mu (F) capacity is obviously insufficient. Will the replacement after recovery R536 commissioning, troubleshooting.9Tiservice manual download site