When failure occurs, disconnect SC20 and SU board and SD board, to boot, not protection, that problem in SC. From SC plate lamp is not lit when the phone is switched on analysis of fault in the energy recovery circuit check of energy recovery circuit has been found that the waveform after startup socket SC20 19 feet boot drive signal, check D board found socket D20 19 feet be bent. Processing after correction D20 socket, troubleshooting.cvYservice manual download site