This machine can be powered, led lights, boot LOGO screen but only for a few seconds and dark on the screen.

Normal switches, indicating normal keys and drive circuit board circuit; a back light is out, while dark, show that the fault may pressure plates and lamps, but does not rule out the power supply is bad. Because when Exchange components in DC switching power supply output increases, can lead to high voltage plate power supply protection for lack of effective current.

Teardown revealed that the secondary filter capacitor switching power supply of the machine has more than one drum kit, C14, C661, C662, C663, C441, C442 have bump leakage, thereby determining the monitor used for a long time, machine internal temperature too high capacitor bulge loss volume, leading to high voltage +13V power supply Board bad high voltage Board protection.


Secondary switching power supply capacitor leakage, if it is +5V power supply bad, doesn't switch occurs, boot after flashing LEDs and so on.

After the bulging capacitors replaced, troubleshooting, display the normal switch with backlight normal, normal image.

For power supply replacement, should pay attention to capacitance and capacitance of the lost capacity, should not be too large, avoid causing secondary power on momentary charge current rectifier diode damaged, primary IC damage, failure of the power tube new.

During the maintenance period should note that for switching power supply secondary tend to use several capacitors in parallel, rather than using a large capacitor, the main reason was to decrease capacitor failures caused by machine failure, because a capacitor failure rate is far greater than the number of capacitor failure rate. Several capacitors in parallel, even if there is a loss of capacitance tolerance, other capacitor if the normal, the machine still works.