Do these also apply to PSUs?

[don_svetlio]

Shot noise

Main article: Shot noise

If electrons flow across a barrier, then they have discrete arrival times. Those discrete arrivals exhibit shot noise. The output of a shot noise generator is easily set by the current. Typically, the barrier in a diode is used.^[3]

Shot noise in electronic devices results from unavoidable random statistical fluctuations of the electric current when the charge carriers (such as electrons) traverse a gap. The current is a flow of discrete charges, and the fluctuation in the arrivals of those charges creates shot noise. Shot noise is similar to the noise created by rain falling on a tin roof. The flow of rain may be relatively constant, but the raindrops arrive discretely.

The root-mean-square value of the shot noise current i_n is given by the Schottky formula

where I is the DC current, q is the charge of an electron, and ΔB is the bandwidth in hertz.

The shot noise assumes independent arrivals. Vacuum tubes have shot noise because the electrons randomly leave the cathode and arrive at the anode (plate). A tube may not exhibit the full shot noise effect: the presence of a space charge tends to smooth out the arrival times (and thus reduce the randomness of the current).

Conductors and resistors typically do not exhibit shot noise because the electrons thermalize and move diffusively within the material; the electrons do not have discrete arrivial times. Shot noise has been demonstrated in mesoscopic resistors when the size of the resistive element becomes shorter than the electron-phonon scattering length.^[4]

Flicker noise

Main article: Flicker noise

Flicker noise, also known as 1/f noise, is a signal or process with a frequency spectrum that falls off steadily into the higher frequencies, with a pink spectrum. It occurs in almost all electronic devices, and results from a variety of effects, though always related to a direct current.

Burst noise

Main article: Burst noise

Burst noise consists of sudden step-like transitions between two or more levels (non-Gaussian), as high as several hundred microvolts, at random and unpredictable times. Each shift in offset voltage or current lasts for several milliseconds, and the intervals between pulses tend to be in the audio range (less than 100 Hz), leading to the term popcorn noise for the popping or crackling sounds it produces in audio circuits.

Source: Wikipedia

[flibberdipper]

English please?

[don_svetlio]

English please?

PSU has been making a silent tick/click noise for about a week without any noticeable signs of failure (no system resets, no random shut downs/reboots, no missed POSTs) so I thought it might be electrical noise and decided to google it. It might seem that way if the rain effect one applies to PSUs since the sound is very inconsistent (sometimes there for a few hours, sometimes gone for days).

[flibberdipper]

PSU has been making a silent tick/click noise for about a week without any noticeable signs of failure (no system resets, no random shut downs/reboots, no missed POSTs) so I thought it might be electrical noise and decided to google it. It might seem that way if the rain effect one applies to PSUs since the sound is very inconsistent (sometimes there for a few hours, sometimes gone for days).

Or... It could be a fan. Which is probably more likely.

[don_svetlio]

Or... It could be a fan. Which is probably more likely.

True. Come to think of it, when the PC stops, usually I hear a few (2-3) slow clicks. Is that too bad? I need to have my face in it to hear it.

EDIT: Voltages reported by Software are ok (Aida64 reports normal readings with the GPU 12V between 12.22 and 12.25 on idle and 12.09 and 12.16 under load)

[flibberdipper]

True. Come to think of it, when the PC stops, usually I hear a few (2-3) slow clicks. Is that too bad? I need to have my face in it to hear it.

EDIT: Voltages reported by Software are ok (Aida64 reports normal readings with the GPU 12V between 12.22 and 12.25 on idle and 12.09 and 12.16 under load)

Well if it's the fan slowing down, then of course they're gonna be slower.

[don_svetlio]

Well if it's the fan slowing down, then of course they're gonna be slower.

Yup, it's the fan. Turned the PC off and noticed the ticking and it slowly stopped. Booted up and it started up and ramped up then disappeared and can only be heard randomly.

The question is, can it do any damage? I doubt it's hitting something important since it would have sliced through it sooner, not after a week of regular use.

[flibberdipper]

Yup, it's the fan. Turned the PC off and noticed the ticking and it slowly stopped. Booted up and it started up and ramped up then disappeared and can only be heard randomly.

The question is, can it do any damage? I doubt it's hitting something important since it would have sliced through it sooner, not after a week of regular use.

Probably not. The chances of it actually hitting something repeatedly are pretty low IMO.

[don_svetlio]

Probably not. The chances of it actually hitting something repeatedly are pretty low IMO.

My thoughts as well. Probably a dried up bearing or it got slightly misplaced when I tilted the case with the fan running a week ago.