Teledyne 6200E - Sulfides Analyzer - Manual (Page 255)

Model 6200E Instruction Manual TROUBLESHOOTING & REPAIR
M6200E Rev: A1 255
You can verify this failure by logging on to the instrument using APICOM or a terminal program. If
the analyzer responds to remote commands and the display changes accordingly, the display
wiring or the I
2 C bus may be faulty.
11.5.7. Relay Board
The relay board circuit can most easily be checked by observing the condition of its status LEDs as
described in Section 11.1.4, and the associated output when toggled on and off through the
SIGNAL I/O function in the DIAG menu, see Section 6.9.2.
If the front panel display responds to key presses and D1 on the relay board is not flashing, then
either the I2c connection between the motherboard and the relay board is bad, or the relay board
itself is bad.
If D1 on the relay board is flashing, but toggling an output in the Signal I/O function menu does
not toggle the output’s status LED, the there is a circuit problem, or possibly a blown driver chip,
on the relay board.
If D1 on the Relay board is flashing and the status indicator for the output in question (heater,
valve, etc.) toggles properly using the
Signal I/O function, but the output device does not turn
on/off, then the associated device (valve or heater) or its control device (valve driver, heater
relay) is malfunctioning.
Several of the control devices are in sockets and can easily be replaced. The table below lists the
control device associated with a particular function:
Table 11-6: Relay Board Control Devices
FUNCTION CONTROL DEVICE SOCKETED
Valve0 – Valve3 U5 Yes
Valve4 – Valve7 U6 Yes
All heaters K1-K5 Yes
11.5.8. Motherboard
11.5.8.1. A/D functions
A basic check of the analog to digital (A/D) converter operation on the motherboard is to use the
Signal I/O function under the DIAG menu. Check the following two A/D reference voltages and
input signals that can be easily measured with a voltmeter.
• Using the Signal I/O function (Section 6.9.2 and Appendix D), view the value of
REF_4096_MV and REF_GND. If these signals are within 10 mV and 3 mV, respectively,
of their nominal values (4096 and 0) and are stable to within ±0.5 mV, the basic A/D
converter is functioning properly. If these values fluctuate largely or are off by more than
specified above, one or more of the analog circuits may be overloaded or the motherboard
may be faulty.
• Choose one parameter in the Signal I/O function such as SAMPLE_PRESSURE (see
previous section on how to measure it). Compare its actual voltage with the voltage
displayed through the
SIGNAL I/O function. If the wiring is intact but there is a difference
of more than ±10 mV between the measured and displayed voltage, the motherboard may
be faulty.