First, resolve the issue with the RI return signal.
Ensure that the RI signal is properly connected and functioning correctly.
Additionally, measure the signals in the voltage domains to assess their integrity.
Check the ground resistance of LDO is normal or abnormal. If it is abnormal, consider replacing the LDO. If it is normal, test the input voltage of pin 5 to determine if it is sufficient for voltage conversion.
Check if the fixture is functioning properly or if a reboot is required. Verify the reliability and integrity of the fixture.
Investigate any potential issues with the data cable interface. Abnormal resistances at the interface are often the cause.
By performing these checks, you can identify and address any issues related to the fixture or data cable interface that may be causing the abnormal RST reset voltage.
In this case, you should short-circuit the CO signal of the chip and continue the process. If short the output CO signal of chip 1 ,reports asic 1, continue with the rest of the chips. Identify the defective chip that cannot receive the signal and replace it.
Machines that were previously running fine but cannot run after board stacking may not be related to frequency but rather to the BIN (firmware version) used. Try using similar BIN versions, such as BIN4, and check if the A5V1R (ASIC version) is the same.