Since it's highly improbable that the capacitive part of the probe has changed (the capacitor is basically the outer tube and center pin) the most likely cause of your failure is the active electonics (oscillator) at the connection-end of the probe.  It could well be something as simple as a blown transistor or op-amp, either of which are probably readily replaceable and likely cost mere pennies.  If you know an electronics guy who's not afraid of a little board-level troubleshooting you can probably get it fixed for a tiny fraction of what a replacement probe will cost. This assumes, of course, that there is actually some active circuitry at the end of the probe to fail.   Have you done the swappy thing, connecting the apparently good probe from the other tank to the input for the "failed" probe to verify that it's actually the probe and not something internal to the unit, like that channel's input circuitry?  More info, please....

BTW, Electronics International also make capacitive probes, but there is no guarantee that their output would be compatible with your VMI's input.  Such would also be the case with any other mfr's probes.  Scoping the signal from a good probe would at least tell you what kind of input your VMI unit is looking for. 

  <marv>

Mark Quinn <mquinns@aol.com> wrote:

>
> Help,
>   One of my Vision Microsystem 48" capacitance fuel probes bit the dust in
>my 360. Called JPI who will make one (7 days) at a cost of $795. That is
>about five times the original cost. Is there some other source for this kind
>of probe? Thanks  
>    
>
>
> Mark Quinn
> mquinns@aol.com
> Spruce Creek Fly-In