I have two Dell 3007WPF monitors at home and one recently started making a really loud (painfully loud) snapping noise about once an hour. It's like an electrical discharge -- very sharp. There's no change in the display when this happens and as far as I can tell, there isn't any kind of flash or smell from the monitor.
The monitors are plugged into a UPS, if that makes any difference and the one monitor that's exhibiting this behavior is driven by an active DisplayPort to dual-link HDMI converter (my video card only has one dual-link HDMI output and these monitors predate DisplayPort). It's hard to tell if my second 3007WPF monitor at home is doing this because the sound is very short so it's hard to localize it, but I suspect it might also be doing it occasionally.
I'm writing now because I also have a Dell 3007WFP at work, and after 7 years, it has recently started making this snapping noise. It also uses a DisplayPort to dual-link HDMI converter but is plugged directly into an outlet. Again, no change in the display when this happens.
Is this a known failure mode for these monitors? Might it be a dust accumulation problem -- is it worthwhile unplugging the monitor, taking the back cover off and blowing it out? I tried blowing compressed air through the vents without much success.
No, not a Dell documented known issue for this 10 year old model. A search on google for "monitor popping noise" does show some older monitors with the issue. I would be very cautious about removing a monitor back panel. As a rule, we do not recommend disassembling a monitor which is why there are no instructions to do so in our monitor User's Guide.