When the single board test shows that the number of chips is incomplete, it means that the power supply unit of the hash board is normal, and the faulty chip can be found by checking the RXD, TXD, and CLK signal voltages of the chip.
1. First, measure the RXD signal voltage (the RXD signal voltage is transmitted from the first to the last), and then measure the TXD signal voltage (the TXD signal voltage is transmitted from the last to the first). Generally, check the RXD and TXD of the first and last chips. Under normal circumstances, their signal voltages are both 1.8V.
2. To measure the CLK signal voltage again, measure the last chip of each CLK signal corresponding to the chip. The normal signal voltage is 0.9V.