Dave, Check the O-rings (drain and fill)! Moving the Prism probably meant switching it off. When the O-ring cool down become brittle, and more frequently than not do leak. If as said you have checked all the obvious, that would be my best bet. Clemente >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) -- ******************************************* Dr. Clemente Recio Laboratorio de Isótopos Estables Fac. de Ciencias Univ. de Salamanca Plaza de la Merced, S/N E-37008 SALAMANCA SPAIN Phone: (+34) 923 29 45 00, Ext. 1540 (Automatic Switchboard) Fax: (+34) 923 29 45 14 E-mail: [log in to unmask] Web page: http://www.usal.es/isotopos *******************************************