The method of maintaining main board’s power

2019-11-16

Check whether the lighting on the main board’s power switch board and the switch power is normal or not.

Remove the main board and the power switch board, and measure L012 andN3 with the multimeter to see whether there are fo 220V ac voltage input.

Measure the output value(（202＋－)（203＋－）is normal or not.(if the voltage is not normal, need to replace the switching power).

Insert the 202 and 203 into the power switch board, now the lamp on the
power switch board is on(bright all the time), and measure the output voltage of the power
switch board (if the voltage is abnormal, need to replace the new power switch board.)

Insert the power switch board on 201 and 204.

Measure the 201 and 204’s voltage is normal or not, or connect the +- reversely.If connect the +- reversely, which will appear the below situation.

Insert the 201 and 204 into the main board to check the main board’s output value is normal or not.(If the voltage is abnormal, need to replace the main board.)

Insert 18V and 9V into the main board to observe whether the three red lights are normal
(if normal, it bright all the time) and measure whether the 18V and 9V’s output voltage is normal or not.(If the voltage is abnormal, it is the problem of the wiring.)