Teledyne 9110TH - Nitrogen Oxides Analyzer - Manual (Page 254)

Model 9110TH NOx Analyzer Troubleshooting & Repair
Teledyne Analytical Instruments 234
7.5.7. TOUCH SCREEN INTERFACE
Verify the functioning of the touch screen by observing the display when pressing a
touch-screen control button. Assuming that there are no wiring problems and that the
DC power supplies are operating properly, but pressing a control button on the touch
screen does not change the display, any of the following may be the problem:
 The touch-screen controller may be malfunctioning.
 The internal USB bus may be malfunctioning.
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 touch-screen interface may be faulty.
7.5.8. LCD DISPLAY MODULE
Verify the functioning of the front panel display by observing it when power is applied
to the instrument. Assuming that there are no wiring problems and that the DC power
supplies are operating properly, the display screen should light and show the splash
screen and other indications of its state as the CPU goes through its initialization
process.
7.5.9. GENERAL RELAY BOARD DIAGNOSTICS
The relay board circuit can most easily be checked by observing the condition of its
status LEDs as described in Section 7.1.4.3, and the associated output when toggled on
and off through the SIGNAL I/O function in the DIAG menu, see Section 4.13.2.
If the front panel display responds to key presses and D1 on the relay board is not
flashing, then either the wiring between the keyboard and the relay board is bad, or the
relay board itself is bad.
If D1 on the Relay board is flashing and the status indicator for the output in question
(heater, valve, etc.) does not toggle properly using the Signal I/O function, 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 7-8: Relay Board Control Devices
Function Control Device Socketed
All valves U5 Yes
All heaters K1-K5 Yes