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Thermo Fisher Scientific

No beam visible


No beam visible. When opening the column valves the Blanker Shutter Monitor(BSM) shows "Gun Deflector controlled by Auto Blanker“.




These are possible resolutions for the issue:

  • Replaced BSDR and upgraded firmware.


These are possible causes for the issue:

  • BSDR defective.


  1. Check LED of IPB status. When column valves open BSM shows beam still blanked and all LED of IBP are on. While column valves closed all LED on except H11. 
  2. Measure voltage between X5-1 and X5-2 at the IPB. If H11 is not on, then the voltage coming from MBGONIO is not present. Voltages were present when H11 is on when the column valves were open. 
  3. Unplugged all shutters, turned off all cameras and restarted the system, no improvement. 
  4. BSDR no error.

Solution: Problem resolved after replace BSDR and upgraded firmware.


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