First visual check on the circuit board have burn out the fault point, cha + 290 v is normal, and the tube on both ends of the measurement for ac 180 ~ 290 v or so jump, this shows that oscillation circuit has a vibration fault phenomena, but a soft breakdown fault in the circuit board, the oscillation frequency for failing to meet the 14 KHZ, low voltage on both ends of the tube, so can't meet the requirements of bulb light, first to the diodes D5 ~ D8 inspection found no abnormalities, and respectively of capacitor C3 ~ C7 j400v (104) found during C8 inspection capacitance has short circuit breakdown, the capacitance change light back to normal after electrify test tubes.aYAservice manual download site