Teledyne GFC-7000T - Trace CO2 Analyzer - manual - Manual (Page 235)

Troubleshooting Model GFC7000TA Carbon Dioxide Analyzer
Teledyne Analytical Instruments 217
10. TROUBLESHOOTING & REPAIR PROCEDURES
This contains a variety of methods for identifying the source of performance problems with the analyzer.
Also included in this are procedures that are used in repairing the instrument.
CAUTION
The operations outlined in this section are to be performed by qualified maintenance
personnel only.
CAUTION
Risk of electrical shock. Disconnect power before performing the following
operations.
10.1. General Troubleshooting Hints
The analyzer has been designed so that problems can be rapidly detected, evaluated and repaired.
During operation, the analyzer continuously performs self-check diagnostics and provides the ability to
monitor the key operating parameters of the instrument without disturbing monitoring operations.
A systematic approach to troubleshooting will generally consist of the following four steps:
1. Note any WARNING MESSAGES and take corrective action as required.
2. Examine the values of all TEST functions and compare to factory values. Note any major
deviations from the factory values and take correction action as required.
3. Use the internal electronic status LED’s to determine whether the CPU and I 2 C buses are
running, and if the sync/demodulator and relay board are operating properly. Verify that the DC
power supplies are operating properly by checking the voltage test points on the relay board.
Please note that the analyzer’s DC power wiring is color-coded and these colors match the color
of the corresponding test points on the relay board.
4. SUSPECT A LEAK FIRST! Data from Teledyne Instruments’ service department indicates that
50% of all problems are eventually traced to leaks in the pneumatic connections and gas lines of
the analyzer itself, the source of zero air, span gases or sample gas delivery system.
Check for gas flow problems such as clogged or blocked internal/external gas lines, damaged
seals, punctured gas lines, a damaged pump diaphragm, etc.
5. Follow the procedures defined in Section 11.5 for confirming that the analyzer’s basic
components are working (power supplies, CPU, relay board, sync/demod board,
touchscreen/display, GFC wheel motor, etc.). See Figure 3-3 for general layout of components
and sub-assemblies in the analyzer. See the wiring list and diagram in Appendix D of this
manual.