Auburn University JXA-8600 EMPA startup issue

[BillHames]

Dear Microscopists, We have a ~1990 vintage JEOL JXA-8600 EMPA at Auburn University that recently shut down during normal operation and now will not complete a restart sequence.

The essentials seem ok (electricity, cooling water, compressed air, rough vacuum, and the chamber and column are still vacuum tight) but startup does not proceed from starting the rough pump to opening a pneumatic valve to the diffusion pump. I also note a JEOL control console outlet receptacle ('MA19', 100 VAC) we normally use for the Pirani gauge (and receives power through its own relay) now has no power. The original fault was, at least in part, related to failure of the air compressor. However, restoring air pressure through an auxiliary compressor does not enable a complete startup.

Any suggestions are greatly appreciated, and I can endeavor to answer questions with regard to the JEOL circuit diagram schematics (my direct email is hameswe@auburn.edu).  Thanks, Bill

[Probeman]

Dear Microscopists, We have a ~1990 vintage JEOL JXA-8600 EMPA at Auburn University that recently shut down during normal operation and now will not complete a restart sequence.

The essentials seem ok (electricity, cooling water, compressed air, rough vacuum, and the chamber and column are still vacuum tight) but startup does not proceed from starting the rough pump to opening a pneumatic valve to the diffusion pump. I also note a JEOL control console outlet receptacle ('MA19', 100 VAC) we normally use for the Pirani gauge (and receives power through its own relay) now has no power. The original fault was, at least in part, related to failure of the air compressor. However, restoring air pressure through an auxiliary compressor does not enable a complete startup.

Any suggestions are greatly appreciated, and I can endeavor to answer questions with regard to the JEOL circuit diagram schematics (my direct email is hameswe@auburn.edu).  Thanks, Bill

That's a very old instrument! 

First thing I would check is the diffusion pump heater. Try touching (briefly!) the bottom of the diffusion pump and see if it's hot.  I've seen these heaters fail on re-start.