At the beginning of maintenance for shutdown protection. Consult the output pipe line is not damaged, then switch power supply part. UFHservice manual download site
 UFHservice manual download site
See below related circuit. Off operation output transformer (3) feet and D904, with a 300 Ω / 50 w wire wound resistor load and false in ends, C909, boot + B measured voltage 108 v power source is 108 v, apparently caused by abnormal voltage loop output overvoltage protection. Measurement error amplifier tube Q902 Ub =, Ue = 147 v, 146 v Uc: 20 v, prove Q902 has send the error signal. Pulse width measurement control tube Q903 Ub = = 0.67 V, 0.67 V, Uc Q903 pulse width control tasks unfinished. Remove the Q903, measured with type MF64 pointer multimeter R * lk be, be positive and negative resistance is normal, with hEF dc magnification of about 180, normal. The tube remounted, check switch tube Q901, ZD901 elements are normal.UFHservice manual download site