1. Please first check the Voltage.
The APW3+ cannot be used in countries with a main power voltage lower than 205V. The PSU will not start below this voltage.
The APW5 is compatible with one Antminer S9/T9 but ONLY with a 220V input. With a 110V input, we do NOT recommend that APW5 be used to run an Antminer S9/T9.
The APW5 is compatible with one Antminer L3+ with a 110V input or 220V input.
The APW5 can power two Antminer R4 miners with a 220V input but NOT more than one Antminer R4 with a 110V input.
You may find the PSU specifications from the link below:
2. Please then check the PSU.
To check the PSU you can test the machine with a known good PSU. If you do not have another PSU then check by switching the cables between hash boards. If the issue follows the cable then the PSU may be faulty.