No grating, a "squeak" cries, switching power supply has been working, but load over-voltage, over-current protection circuit. The machine line in the output transformer caused the short circuit and open circuit fault is relatively common. eV4service manual download site
 eV4service manual download site
 eV4service manual download site
(1) boot heard "cheep" voice, no grating. First the multimeter measuring switch power supply output voltage + B, only 65 v (normal is 110 v) doubt caused by overloading. eV4service manual download site
(2) with the voltmeter measurement line lose tube emitter resistor R781 on pressure drop of 2.7 V, and a + B should be 2.3 V when the voltage is normal. Now + B65Y, R781 pressure drop increase, that line is greater than the current 350 ma, the load has a short circuit. eV4service manual download site
(3) remove the visual board and deflection coil, + B voltage measurement again, still is 65 v, that flow is not caused by the deflection coil and pressure load, problems in output pipe or line output transformer. eV4service manual download site
(4) to replace with good manager Q781, still for 65 v + B, the fault line has been limited to the output transformer. eV4service manual download site
(5) to replace the new line output transformer, a + B returned to normal, the accelerating voltage and focus voltage, a satisfactory image.eV4service manual download site