Try this device by another power socket in another room.
After the step 2 , the power doesnot go off, then do the test as follows. Step 3: To test the input (L , N , pole) does or doesnot leakage to the shell. If not, it device is ok.
(From the right to left, the third screw is connected to the shell
Step 7: Test this part is connected to the shell or not? If it is connected to the shell,
(When you can test the resistance is small,) then please take this part(blue insulating strip) out of the power supply to see if it is broken.) and if not, it is ok.
It is important, to open the shell, to see if this part (the switching point, or the black part) is on the left side of the power supply or not, if it is on the left, then it is ok. If not, please make it to the left of the device.