Discussing the high-pitched squeal ("coil whine") from APC Back-UPS Pro Gaming every few minutes and seeking a solution.
Discussing the high-pitched squeal ("coil whine") from APC Back-UPS Pro Gaming every few minutes and seeking a solution.
Hello!
I bought an APC Back-UPS Pro Gaming (BGM-series) about 2-3 months ago and have been hearing a loud high-pitched squealing or buzzing coming from inside the unit every few minutes. It’s not the usual beeps or alerts—it sounds like coil whine, which is vibration from inductors or capacitors, lasting a few seconds before stopping.
Details:
- Model: APC Back-UPS Pro Gaming BGM-2200B
- Firmware: Latest PowerChute, UPS firmware up to date
- Load: Around 200 W (desktop PC + monitor), steady
- Mains Voltage: Stable, within 230 V ± 5 %
- Battery: Fully charged at 100 %
- Input Sensitivity: Set to Low via PowerChute
- Self-Tests: Disabled in software
Even with these settings, the noise keeps happening every 1-2 minutes. It doesn’t match on-battery transfer or error sounds; it’s just mechanical/electrical interference inside the UPS. I have a video of the sound. Anyone know how to resolve this?
Thanks for your help!
Well, it might be part of the AVR responsible for that coil whine. If you disconnect the plug from the UPS to the mains, making the UPS switch to battery power to keep the PC running, does the noise persist (excluding the battery power alarm)? In general, it could be a localized problem (such as only your specific UPS model) or a model-specific fault (since all the same series UPSes tend to have the same issue). You might also reach out to APC and inquire about it. After all, they created it.
When operating solely on battery, the noise ceases. Upon connecting to the mains, the noise resumes. I might attempt to reach out via APC.
The sound originates directly from the main power line, passing through surge protection, then through the AVR, and finally reaching the PC. When the PC uses battery power instead of mains, the surge protection and AVR are not active. Instead, the battery DC is sent to an inverter which converts it to AC, supplying it to the PC. Of course, in the direct mains connection, a battery charger is also present, but I suspect it wouldn't turn on every few minutes. A lead-acid battery doesn't discharge quickly enough for the charger to activate continuously, ensuring a full 100% charge at all times. Therefore, the noise is probably caused by either the surge protector or the AVR.