User Guide

Troubleshooting & Repair Teledyne API M100E Analyzer Operation Manual
272
12.6.5. RELAY BOARD
The relay board circuit can most easily be checked by observing the condition of its status LEDs as described in
Section 12.2, and the associated output when toggled on and off through the SIGNAL I/O function in the DIAG
menu, refe
r to Section 6.9.2.
 If the front panel display re
sponds to key presses and D1 on the relay board is not flashing, then either the
I
2
C 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 12-6: Relay Board Control Devices
FUNCTION CONTROL DEVICE SOCKETED
Valve0 – Valve3 U5 Yes
Valve4 – Valve7 U6 Yes
All heaters K1-K5 Yes
12.6.6. MOTHERBOARD
12.6.6.1. 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 (refer to Section 6.9.2 and Appendix D), view the
value of REF
_409
6_MV and REF_GND.
 The nominal value for REF_4096_MV is 4096 mV  10 mV.
 The nominal value for REF_GND is 0 mV  3 mV, respectively, of their nominal values (4096 and 0) and
are
 If these signals 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 (refer to 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.
04515F DCN6048