Agilent DSO7014A power switch

[artag]

I'm starting to have a problem with the power switch on my Agilent DSO7014A scope.
 
It appears to not stay latched on, but actually what's happening is that clicking it from the on state to the off state doesn't always quite complete and it sticks in a state where the power is off but the toggle hasn't completely cycled, so turning it on doesn't latch. Usually several attempts at pushing the button in and then releasing it so that it clicks out FAST will fix it for a while.

I shall strip it down soon and see if I can grease it back to life, but has anyone else encountered this on a 7000 series or, probably it's close 5000 and 6000 relatives ? If it it needs a new switch, are they a commonly available item ? I know HPAK have recently killed the excellent parts availability which helped build their reputation and desirability.