Light meaning and fix
APC Back-UPS All LEDs Flashing: Internal Fault Meaning
On APC Back-UPS guidance, all LEDs flashing simultaneously signifies an internal UPS fault.
On APC Back-UPS guidance, all LEDs flashing simultaneously signifies an internal UPS fault.
What it means
The UPS has detected an internal fault and needs APC support.
Device details
| Device type | UPS battery backup |
|---|---|
| Brand | APC |
| Model | Back-UPS LEDs |
| Light name | All LEDs |
| Light location | UPS front panel |
| Color | Multiple LEDs |
| Pattern | All LEDs flashing simultaneously |
| Severity | danger |
| Last verified | 2026-05-02 |
What to do first
Contact APC technical support with the model number and serial number.
- Do not ignore the all-LED flashing fault.
- Note the UPS model number.
- Note the serial number.
- Disconnect critical equipment safely if needed.
- Contact APC technical support.
- Do not open the UPS unless official service guidance says to.
When this can be normal
This is not a normal operating state.
When to stop troubleshooting
Stop and contact APC support. Internal UPS faults can involve electrical safety risks.
Parts or products that may help
Only replace parts when the light pattern and official guidance support it. Some lights indicate setup or software states, not broken hardware.
- No replacement part is recommended from this light pattern alone. Troubleshoot the device state first.
FAQ
What does all LEDs flashing mean on APC Back-UPS?
Schneider Electric says it signifies an internal UPS fault.
Should I open the UPS?
No. Contact APC support and follow official safety guidance.
What information should I have ready?
Have the model number and serial number ready.
This guide is based on: Schneider Electric APC Back-UPS LED FAQ.
Source type: official_support_page. Confidence: verified. Last verified: 2026-05-02.
UPS internal faults should be handled carefully.