Hi Dave,

You may have to replace the heater plate of the diff, they sometimes go.

Arnold

Dave Mattey wrote:

> We recently moved our ‘89 vintage PRISM and cannot get high vacuum back
> again.  The analyser has pumped out normally to 1e-3 mbar but the diff
> pumps just will not trip back on. Everything seems ‘normal’ ie all power
> supplies on, fuse by the rocker switch is OK etc etc. Has anyone
> experienced this, or know of potential problem areas (sticking relays,
> faulty switches etc) before I am forced to dust off the schematics?
>
> Thanks for  any help!
>
> dave
>
>
>
> -----------
> Dave Mattey BA PhD FRAS
> Professor of Stable Isotope Geochemistry,
> Department of Geology,
> Royal Holloway College,
> University of London,
> Egham Hill,
> Egham,
> Surrey,
> TW20 0EX
>
> Telephone
>
> 01784   443587 (direct line)
>         443582 (dept secretary)
> 07780   697564 (mobile)
>
>
>