I'm also sure it's not the PSU, as I've changed it and it's still screeching.ĮDIT: it's definitely not a digital beep, it's an analog whine. it occurs when the computer is idle, with and without high I/O activity, with and without high CPU usage. The noise doesn't seem to be related to any particular activity, i.e. This noise comes in short bursts (up to 3 seconds long) and the occurrence frequency is unpredictable. For the last 2 years, on hot days only (28C (82F) or more) it makes a high-pitched, quite loud, and very annoying noise.
