[ARC5] Mystery Component

[Robert Eleazer]

I was using my HP6291A variable power supply the other day when it suddenly gave out a sharp sound, "Crack!" and emitted a small but nonetheless alarming amount of smoke, accompanied by a very unpleasant odor.  I shut it off and unplugged it.

Examination reveals that there's the remains of a component that was soldered across the leads to the neon pilot light on the front panel.  On one side I can see "6 pf" and on the other side "Fo = 4,9 MHZ"

When I clipped one of the wires going to the mystery component and then powered up the 6291A, the unit seemed to function normally. 

I assume that the exploded component is some kind of a suppressing filter across the neon tube and possibly also is designed to aid in filtering noise from the AC line.  I have not been able to find the component listed in the service manual.  I'm not aware that it is a normal practice to put a filter across neon pilot lights, but maybe it is.

Any advice?

Thanks, 

Wayne
WB5WSV