Magnetic interference on optical drives?

[sswilson]

I know that CD/DVD players/writers are laser based, and thus wouldn't be affected by EMI or magnetic fields like floppy / tape based media would be, but can anybody think of a good reason why a DVD shouldn't sit directly under a PSU on an open bench?

[3.0charlie]

EMI is part of every electrical component. Though a DVD / CD is based on a laser to read/write, there are still electronics inside to convert the light signal to an electric signal. Thus the possibility of EMI on a DVD player.

EMI may not come from the PSU - SkyMTL can tell you more about those. But the biggest EMI generators are monitors and speakers.