Agilent 33410A Noisy Fan or Normal?

[K1JOS]

I just got a used 33410A and so far it seems to work perfectly and in excellent shape.  However, the fan appears much noisier than I expected sounding almost like the noise one hears from a drafty window on a windy day.  More troubling than the noise is the varying pitch of the low-pitched whistling exhaust making me worried about a power supply stability problem.  I have not disassembled it yet as I ahve a right to return it.  The meter is spotless without dirt/dust apparent.  Apart from opening it up and checking the fan voltage for stability , any other advice would be appreciated.

Jerry

[Noise Floor]

What's the build date?  You mention you have the right to return it, is it from a used/rental retailer?  If so, see if you can listen to an identical model and see if it sounds the same.

[K1JOS]

It was a remote purchase - i live in the sticks :-)

jerry