How to test Antminer hash board one by one?

1. Make sure that the power supply (the lights can be found), the control board (the miner status can be found) and the two fans can work normally.

2. Make sure that one tested hash board is connected to the control board and power supply, and disconnected from the remaining two hash boards.

Connect the hash board, control board and power supply as shown below:

Normal miner status of testing hash board：