Determine which Hall needs to be replaced

①

 24 channels, but the upper left corner of the module shows 0. 

 How to judge which Hall is faulty? The method is to insert the 

 cable into each Hall separately, the correct one should display 

 4, the incorrect one will display 0, replace the Hall with 0.

②

 As shown in the figure above, assuming that the 5-8 channels  

 are negative, I want to replace the second Hall, so how to

 determine which one is the second Hall?
 The method is: the first Hall to which the cable is connected

 is channel 1-4, whether the cable is on the left or right。