Waters GCT Premier Operator's Manual page 270

No Beam or Emitter current (in FI source):
Possible cause
Probe is incorrectly position.
No extraction voltage or current
leakage occurring.
Emitter is damaged.
Excessive leakage current (in FI source):
Possible cause
Internal source wiring is touching
grounded elements.
Continued high leakage current.
11-12 Troubleshooting
Corrective action
Determine whether the position of
the emitter is correct. Using the
emitter probe, adjust the knob.
Inserting the FI/FD inner
See also:
source probe on page
Ensure the extraction voltage read-
back is present and the leakage
current is less than 10 mA.
See also: Obtaining a beam and
tuning in FI operation on page
Ensure that the emitter is not
damaged by visually inspecting the
emitter wire. Check the emitter
current readbacks match the set
values. Replace the emitter if
required or check continually with a
multimeter.
Changing an emitter on
See also:
page 10-33.
Corrective action
Inspect the source and move the
wires.
Inspect the source. Strip and clean
the source if required.
9-11.
9-21.