Spectrometer Header, Pre-Amp Board J1 Pin Assignments - Agilent Technologies VS Series Operation Manual

c. Re-measure the voltage at the PRESS pin. The voltage should be 0. If a constant
steady state voltage is measured, replace the pre-amp board.
Table C-1 gives the spectrometer header, pre-amp board J1 connector pin assignments.
Table C-1 Spectrometer Header, Pre-amp Board J1 Pin Assignments
Chamber
Filament #1
Both Filaments No Emission error message appears on the front panel display
This error can also occur during normal operation.
Causes/Resolutions
1. Both filaments are an open circuit due to age and prolonged normal everyday use:
Spectrometer - Pre Amp Board (Figure C-2 and Figure C-3 on page C-7): Measure
the J2 connector filament resistance (with power off) (filament resistance < .5 Ohm).
If filaments are open circuit, open the spectrometer and replace the filaments. See
Section B.13 "Filament Replacement".
2. Ion Source board failure:
a. Ensure that the ion source board cable is secure at both the spectrometer and ion
source board.
b. If both filaments failed prematurely and both were replaced:
C-8
VS Series Component Leak Detector
Many components of the leak detector are static sensitive.
CAUTION
Wear a grounding device when performing any maintenance
on the leak detector, especially when performing maintenance
of static sensitive parts, such as circuit boards and the
spectrometer.
Repeller
Filament #1
Run a full calibration (Figure C-2 on page C-7 and Figure C-3 on page C-7) and
after a successful pass, measure the voltage of the filament that is in use on the
Pre-Amp board J2 connector (Spectrometer Header). The filament voltage
should = 1.4 to 1.9 VDC with < 30 mV of noise (AC). If not, go to the Manual
Tuning screen and adjust the Emission Current until the AC ripple is < 50 mV
and the filament voltage is 1.4 to 1.9 VDC.·
Select Setup Menu > Manual Tuning screen and note the Emission Current.
Measure the emission current (actually VDC) on the Ion Source board at test
points EMISS T.P and TP101 FIL GND. The measured voltage should correspond
to the observed reading in the Manual Tuning screen (within +/- 10%). If the
emission current <.3 mA, the system senses no emission current, indicating that
the filament is defective. Replace the filament.
Filament #2 Filament #2