Warning: Capacitors can hold a 400V charge. Discharge safely with a resistor (10k ohm, 5W) before touching the board.
. This means the UPS has detected a short circuit while trying to provide battery power, or the internal hardware that converts battery power to AC has failed. JustAnswer Immediate Troubleshooting Steps apc ups power system error 02000 link
: Power down the UPS and unplug it from the wall. Warning: Capacitors can hold a 400V charge
If the error persists after a restart, the cable is the most likely culprit. Replace the communication cable with a known working APC original cable. apc ups power system error 02000 link
While this error usually requires a replacement or professional repair, you can attempt these steps to rule out a temporary glitch: