A:Answer If the UPS continues to flash lights and beep, the UPS probable has an internal fault. I've had one UPS get zapped by a power surge. You will need to contact APC regarding this condition. If the UPS is running normally now and you can connect the UPS to a computer with the PowerChute application installed, you can check to see what the load on the UPS is. Another way is to unplug the UPS from the wall and see if it operates normally when it switches to battery. If it starts flashing lights and beeping you are probably overloading the UPS.