Yeah, this one's common. It's usually coil whine from the power supply or backlight circuitry, and it's often more noticeable at specific brightness levels.
- Try adjusting the screen brightness through the OSD menu. Set it to 100% or down to 50% and see if the noise changes or stops.
- Check if the noise is coming from the audio-out port area. If you have speakers connected to the monitor's audio-out port, try unplugging them to rule out audio feedback.
IF THAT DIDN'T WORK: The noise could be exacerbated by a specific input signal or refresh rate. Try switching from DisplayPort to HDMI, or vice versa, using the appropriate cable. Also, ensure all cables, especially the power cable, are seated firmly to prevent any vibration.
HEADS UP: Minor coil whine isn't typically a sign of failure, but if the noise is loud, changes significantly, or is accompanied by a burning smell, power off the monitor immediately and contact Dell.