are PC power supplies insulated from earth?

[ELS122]

stupid question but is the ground in my pc connected to earth?

[wraper]

Of course it is. There is 3 prong mains connector in PSU for a reason.

[Zero999]

stupid question but is the ground in my pc connected to earth?

Are you talking about the 0V rail? If so, I believe it's normally connected to earth.

[Brutte]

stupid question but is the ground in my pc connected to earth?

That depends on the design of power supply.

If your PC is desktop and it is connected to three-prongs mains receptacle then yes.

But if this PC is a laptop with two-prongs(end to end) supply, or a laptop with three-prongs(end to end) supply connected to unearthed mains receptacle then the answer is: the only connection between earth and GND is via capacitive coupling of a transformer (<1mA) and MOV(>1kV).

Of course this "floating" does not include a situation when you use two-prongs mains supply and ground laptop through USB shield to your printer which might be earthed.

[ELS122]

well yeah, now it seems obvious. I just had a brain fart moment I guess.
and also I found out that if your laptop power brick has a square on its label and it has a 2 prong chord it's insulated from the mains, including earth.
otherwise, if it doesn't have that box and has a 3 prong chord it's not isolated!

[Brutte]

(..) square on its label (..)

This is class II protection class although I am not sure if this guarantees that the secondary side is unearthed..

[Etesla]

Yes, but if your intention is to break this connection (for example to hook up multiple power supplies in series for a higher voltage  ), it is certainly possible.

[ELS122]

No, I just am troubleshooting noise from a interface.

[pcmad]

yes earth ground  is the same as chassis ground on a desktop pc