MKS Granville-Phillips 358 series, Instruction Manual

Page: 107 / 122

Service
Series 358 Micro-Ion Controller Instruction Manual - 358013 - Rev. B
107
Op
er
ation
C
a
p
a
cita
nce Ma
nom
eter
Servic
e
Pre
p
a
ring
fo
r
Op
er
atio
n
8.3 Troubleshooting
If any of the conditions described above have occurred, troubleshooting is
required to determine the repairs that are necessary.
Table 8-1 Symptoms and Possible Causes
Symptom Possible Cause
Unit will not power-up, no response to
power switch Power fuse blown
Wrong line voltage selection, see Line Voltage on page 53
Power fuse blows repeatedly Wrong fuse rating
Wrong line voltage selection, see Line Voltage on page 53
Micro-Ion gauge will not turn ON, or
turns on briefly then shuts OFF Micro-Ion gauge at too high pressure
Auto turn ON/OFF circuit in Convectron gauge module is shutting OFF the
Micro-Ion Gauge
Emission current setting wrong for pressure in gauge
Improper Micro-Ion Gauge connector hookup
Badly contaminated Micro-Ion Gauge
Damaged or contaminated cathode coating, will not sustain emission
Short in Micro-Ion Gauge cable
Short between Micro-Ion Gauge electrodes
Open cathode in Micro-Ion Gauge
Micro-Ion gauge display shows a
steady number when the Micro-Ion
gauge is OFF CAL switch is not in the OFF position
Convectron Gauge display reads a
fixed (non changing) pressure Micro-Ion Gauge IG AUTO switch is left in the set position or the Convectron
option
Pressure reading is higher than
expected Micro-Ion Gauge contaminated
UHV pressure range is not selected appropriately (pressure is below 1 x 10
–7
Torr)
Interference from other ion source
Poor conductance in gauge's vacuum connection to chamber
Gas source in plumbing to gauge, such as leak or contamination
Chamber pressure high because of leak, contamination, or pump failure
Poor location selected for gauge
Faulty gauge or power cable
Faulty electrometer
Degas will not turn ON System pressure above 5 x 10
–5
Torr
Micro-Ion Gauge not turned ON
Micro-Ion Gauge shuts OFF when
degas is initiated Degas fuse blown
Badly contaminated Micro-Ion gauge.