MKS Granville-Phillips 358 series, Instruction Manual

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Chapter 8
112
Series 358 Micro-Ion Controller Instruction Manual - 358013 - Rev. B
8.6 Capacitance Manometer
Troubleshooting
Refer to Figure 4-5 on page 60 to locate the LEDs on the capacitance
manometer printed circuit board.
8.7 Process Control
Troubleshooting
If the
μ
P FAILURE LED is illuminated or flashing, there is a probable circuit
failure. Return this product for repair at a service facility designated by
Granville-Phillips.
The setpoints are read from non-volatile memory into RAM when the unit
powers up. On power up, a checksum is computed and stored in RAM, and
is updated whenever a setpoint is changed. It is then periodically
re-computed from the existing setpoints and checked against the
pre-existing value. If for any reason (such as a power fluctuation or
electrical transient in the system) a setpoint becomes corrupted, this method
will trap the error.
If a setpoint is found to contain garbled data which cannot be interpreted as
a valid setpoint, the setpoint presure will be set to 0.
Table 8-4 Capacitance Manometer Troubleshooting Guide - See Figure 4-5 on page 60
Symptom Possible Cause
Unstable reading Mechanical vibration of capacitance manometer, faulty system ground or cable ground
Display always reads 0 Capacitance manometer cable unplugged, no ± 15 V power, faulty cable
-15V Overcurrent LED is ON -15 V overcurrent. Defective cable, transducer, or circuit board
CG Unplugged LED is ON The Convectron Gauge is unplugged
A/D Failure LED ON A/D failure. Defective Normally Open converter circuit
+15V Overcurrent LED is ON + 15 V overcurrent. Defective cable, transducer, or circuit board
Convectron Bridge Out LED
is ON Defective PC board, Convectron bridge circuit
CG Overcurrent LED is ON Convectron overcurrent. Defective gauge or cable
μ
P Failure LED is ON Microprocessor failure