Anyone tried running PS Audio P-300 with no fan ?

Go ahead! My PS 300 is feeding the Wadia 270 transport, the Wadia 27ix DAC, the AudioResearch SP14 and a Sony DAT-Recorder. No problem whatsoever. Display reading 80 watts.
It's HOT, yes, but I don't care. The Multiwave II upgrade has cooled things down a bit, though. Just make sure that the PS 300 can "breathe" top, bottom left and right and you'll be ok.- If still in doubts ask Paul McGowan (PS-Audio owner), he is very friendly and will answer all kinds of questions - a pro to all PS-Audio gear by the way.
Good lcuk!

After checking with PS Audio, I disconnected the blasted thing as it simply made to much noise. While it ran pretty hot it operated without a hitch.

Yes. I still own one of the original P300s with original Arrow Hart orange color duplex outlets. However, it shuts down when I connect my 100 w/ch power amp along with the preamp, transport and DAC. Appears to work only with low power draw front-end components.