When the Antminer S9j kernel log shows that Chain  has 0 asic (as shown in the figure below), which aspects can be used for troubleshooting?
1. Swap the data cable of the Antminer S9j hash board that shows "has 0 asic" with other normal data cables of the hash board (only the side of the hash board is exchanged), to exclude the problem of the data cable and the Antminer S9J control board.
2. Check whether the total voltage domain is normal. If abnormal, you need to use a fluke 17B+ multimeter to check whether the PIC chip, MOS tube and boost circuit are abnormal.
3. To measure whether the RI signal is normal, it is generally not necessary to check next to each other. For example, in the middle domain, find the RI signal of a group of chips on the edge of the domain for detection. If it is normal, we will check it forward. If it is abnormal, check it backward (the transmission direction of the RI signal is from the last chip to the first chip).
4. If the backstage log and test fixture detection both show "ASIC=0 or No hash board", mainly check whether the voltage of the chip's RI signal and the ground value are abnormal. If there is any abnormality, most of them are caused by the chip pseudo soldering. You can re-solder 2 times first. If it cannot be solved, replace the faulty BM1387 chip.