It sometimes normal and sometimes fail, originally thought poor thermal stability of the circuit components, the use of "cooling" failure to find fault. Again to fault analysis carefully, according to the grating slant green and have the characteristics of flyback line judge fault may be put in tube or output circuit. Touch a phenomenon after the examination, the tube does not exist. Boot monitor tube three cathode voltage, found that the green pin voltage on the low side, remove the tube measurement again, the result is still a bit low. Then test related to the green signal depending on the output circuit element, are found no abnormalities. Then remove the header respectively test three cathode of resistance, resistance measurement results for the green signal pin is small, it is not normal phenomenon. Have relevant parts of the test no abnormalities are found, and then to check the circuit (circuit as shown in figure 2) is suspected discharger SKG01 leakage caused. Try to get off SKG01, mount header commissioning two days are normal, make users to use two months did not fail, proved discharger SKG01 leakage, make the grating slant green, leakage current and beam current increase, colorful display also entered into a state of protection without light.H5hservice manual download site