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Thermo Fisher Scientific

Readback value doesn’t change with Mono shift X


Readback value doesn’t change with Mono Shift X after gun replacement


Titan 80-300


These are possible resolutions for the issue:

  • reconnect MFB connector


These are possible causes for the issue:

  • MFB not fully connected


  1. Previously there was a issue where mono beam shape was abnormal with excitation and later it was tested that mono hardware is defective. After replacing gun assy this beam issue was solved but there was another issue. During Mono shift X, in “output” tab, Set and Ref value will change, but Readback value will not change
  2. Follow 100493 to perform the Insulation and Capacitor check.
    1. Insulation Check: Cage wrt I+ and I- is slowly reaching to OL (Pass), so this is OK. All the other values reached immediately to pass (OL)
    2. Capacitor Check:
      V+62, V- 61, E1 103, E2 100, E3 100, E4 107, I-=I+=185, so those values are also OK although ideally V+ should be identical to V-, E1,E2,E3,E4 value should be the same and as close to the spec as possible
  3. Replaced SDC2, GMS, DPA2, CPB did not fix the issue
  4. Found Mohm between I+ and I- and the spec is around 20Ohm, followed the line and reconnected X20 1-2 and X21 15-16, issue resolved



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