Teledyne 9110T LCD/DISPLAY Module, Motherboard, Test Channel / Analog Outputs Voltage

Model 9110T NOx Analyzer Troubleshooting & Service

12.7.3. I2C BUS

Operation of the I2C bus can be verified by observing the behavior of D1 on the relay PCA & D2 on the Valve Driver PCA. Assuming that the DC power supplies are operating properly, the I2C bus is operating properly if D1 on the relay PCA and D2 of the Valve Driver PCA are flashing

There is a problem with the I2C bus if both D1 on the relay PCA and D2 of the Valve Driver PCA are ON/OFF constantly.

12.7.4. LCD/DISPLAY MODULE

TOUCHSCREEN INTERFACE

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.

12.7.5. RELAY PCA

The Relay PCA can be most easily checked by observing the condition of the status LEDs on the Relay PCA (see Section 12.3.2), and using the SIGNAL I/O submenu under the DIAG menu (see Section 12.1.3) to toggle each LED ON or OFF.

If D1 on the Relay PCA is flashing and the status indicator for the output in question (Heater power, Valve Drive, etc.) toggles properly using the Signal I/O function, then the associated control device on the Relay PCA is bad.

Several of the control devices are in sockets and can be easily replaced. The following table lists the control device associated with a particular function:

Table 12-8: Relay PCA Control Devices

FUNCTION

All valves

Reaction Cell Heater

NO2  NO Converter heater

Permeation Tube Heater for

Optional Internal Span Gas Generator

CONTROL DEVICE	SOCKETED
U5	Yes
K1	Yes
K2	Yes
K4	Yes

12.7.6. MOTHERBOARD

12.7.6.1. Test Channel / Analog Outputs Voltage

The ANALOG OUTPUT submenu, located under the SETUP  MORE  DIAG menu is used to verify that the 9110T analyzer’s three analog outputs are working properly. The test generates a signal on all three outputs simultaneously as shown in the following table:

Teledyne Analytical Instruments 285