What Does This Error Mean?

CyberPower UPS producing no output usually means the overload protection has tripped or the unit has entered a fault state. Disconnect all equipment, power off the UPS completely, wait 30 seconds, then power on with no load before reconnecting devices.

Affected Models

CyberPower CP600LCD
CyberPower CP850PFCLCD
CyberPower CP1500AVRLCD
CyberPower OL1000RTXL2U
CyberPower (all models)

Common Causes

Overload protection tripped — connected load exceeded the UPS rated output watts
Short circuit on an output socket from a faulty connected device
Battery fully discharged during a power cut — UPS shut down automatically
UPS in standby or ECO mode with output voltage sensing disabled
Output relay fault — internal relay failed to engage after startup

How to Fix It

Disconnect all equipment from the UPS.

Remove every device from all UPS output sockets — both the battery-backed outlets and the surge-only outlets. This clears any overload or short circuit condition.
Power off and restart the UPS.

Press and hold the power button until the UPS turns off completely. Wait 30 seconds. Power on again and verify the display shows normal mains power status.
Test with a single simple device.

Connect one low-power device (a lamp or phone charger) to the battery-backed outlet. If the device receives power, the outlet is working and a previously connected device was causing the fault.
Check the total load against the UPS watt rating.

Sum the wattage of all devices you normally connect. CyberPower UPS units are rated in VA and watts — use the watt figure (typically 60% of VA). A 1500VA model has approximately 900W output capacity. If your load exceeds this, the UPS will trip.
Check battery charge level.

If the UPS discharged completely during an extended power cut, some models require several minutes of mains reconnection before output is re-enabled. Connect the UPS to mains and leave it for 5 minutes before testing output.

When to Call a Professional

If the UPS starts, display shows normal, but outputs deliver no power with no overload indicated, the output relay or inverter has failed. Contact CyberPower support.