Thermo Electron 8600 Series, Troubleshooting Service Manual

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2.1 Symptom: Probe 1, 2, 3, or 4 Failure Alarm - SINGLE PROBE FAILURES
Order Possible Cause Verification Action
Probe
Unplugged. Re-seat connector. Re-seat all connections.
1
Not fully seated Verify wires are fully seated in connectors and
connectors are seated together Replace probe if necessary.
Bad probe
Short.
Open.
Display reads 99.
Verify probe resistance. See
Temperature vs. Resistance Chart
(Page 3-2).
Replace probe.
2
Wrong value. Verify probe resistance. See
Temperature vs.
Resistance Chart
(Page 3-2).
Replace probe.
3
Micro board.
Temporarily switch suspect probe with control or
heat exchanger probe. If the same error exists, replace micro board.
2.2 Symptom: Probe 1, 2, 3, and 4 Failure Alarm – (ALL PROBES FAIL)
Order Possible Cause Verification Action
Re-seat connector.
1
Control probe not installed.
Startup only
.
Verify wires are fully seated in connectors and
connectors are seated together.
Reinitialize (re-start) unit.
Reseat all connections.
Replace probe if necessary.
Bad control probe
Display reads 99.
Bad control probe will also
cause a high temperature alarm and lock both
compressors on.
2
Short.
Open.
Wrong value. Verify probe resistance with
Temperature vs.
Resistance Chart
(page 3-2).
Replace probe.
3
Micro board.
Temporarily switch control probe with heat
exchanger probe. If the same error exists, replace micro board.
4
Micro board EEPROM Problem still exists after re-initializing unit. Re-initialize eeprom in test mode. If problem
remains, replace the micro board. Note: all
calibration, set points and configuration are set to
default.