MKS Stabil-Ion 370 Series, Instruction Manual, Page: 108 / 122

7 Service and Maintenance
7-4
Series 370 Stabil-Ion Instruction Manual - 370119
7.3 Fault Relay
The factory installed Stabil-Ion Remote Control Unit is equipped with a “Fault”
relay. The SPDT relay contacts are located on the remote output connector (See
Figure 7-1). The relay is energized when no fault condition is detected. The
relay is de-energized when:
■
There is a fault condition detected by one of the microprocessors.
■
There is a microprocessor failure causing the watchdog timer to reset.
■
Power is lost due to Power Supply failure.
■
Power is removed from the instrument.
■
The power switch is turned OFF.
The source of the fault signal can be determined by observing the fault indicating red LED's and the
Power Supply monitor's green LED's located beneath the Control Unit's cover (see Figure 1-8 on page
1-6). A list of specific causes are described in Table 7-2 on page 7-5.
IG pressure readout very erratic. IG badly contaminated.
Improper IG or Controller grounding.
Bad collector cable.
Excessive noise source.
Interference from other charged particle source in chamber.
Faulty electrometer.
Green +18 LED out on control
board. Improper connection of Power Supply cable.
+18 volt supply to relays faulty.
Green +15 LED out. +15 volt supply faulty (power to analog circuitry and RS-232).
Green -15 LED out. -15 volt supply faulty (power to analog circuitry and RS-232).
Green +5 display LED out. +5 volt supply to display LED's faulty.
Green +5 logic LED out. +5 volt logic supply faulty.
Figure 7-1 Control Board Top
View Showing Green
Power Indicator LED’s
Symptom Possible Cause