High-pitched noise

[Hamlet]

Got an annoying high-pitched noise comming from my 4000. It's very similar to the noise a TV produces, but this one varies a bit up and down.

I've tried locating it, but it's kinda hard in a packed 4000D. So far my best bet is the PSU. Anyone recognize this?

Rgds,
/Hamlet

[Framiga]

Hi

PSU switch-mode transformer.

Sometimes you can fix/reduce it, with a spray varnish insulator

for HT TVset transformer.

Pay attention with an open PSU (hi voltage)

Ciao

[Hyperspeed]

Well I'm no techie but it sounds like a capacitor...

Is it from the A4000 or the monitor? There was an article here before
about the A4k's electrolytic capacitors aging. Maybe a more
technically minded person can walk you through isolating the problem.

I've had some weird noises from my Amiga before - sometimes when I
crash my scandoubler will squeak like a mouse (unless it's just the
monitor going funny at the video signal).

Also, I've heard a Quantum Fireball on a PC with bearing trouble and
it sounds like a ping-pong ball going up and down.

I once had a PDA that used only solid state hardware and on a quiet
night you could hear the processors, like a faint hissing noise. This
could just have been the power fluctuation to the speaker though.