Teledyne t320u Manual Do Utilizador

Página de 426
Troubleshooting and Service 
Teledyne API – Model T300/T300M CO Analyzer 
280 
12.5.4. TOUCHSCREEN INTERFACE 
Verify the functioning of the touchscreen by observing the display when pressing a 
touchscreen control button. Assuming that there are no wiring problems and that the DC 
power supplies are operating properly, if pressing a control button on the display does 
not change the display, any of the following may be the problem: 
  The touchscreen 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 to any of the communications ports. If the analyzer responds to remote 
commands and the display changes accordingly, the touchscreen interface may be faulty. 
12.5.5. 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 with logo and other indications of its state as the CPU goes through its 
initialization process. 
12.5.6. RELAY BOARD 
The relay board PCA (P/N 04135) can be most easily checked by observing the 
condition of the its status LEDs on the relay board, as described in Section 12.1.4.3, and 
the associated output when toggled on and off through signal I/O function in the 
diagnostic menu, see Section 12.1.3.   
1.  If the front panel display responds to button presses and D1 on the relay board is 
NOT flashing then either the wiring between the touchscreen and the relay board is 
bad, or the relay board is bad. 
2.  If D1 on the relay board 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 board is bad.   
  Several of the control devices are in sockets and can be easily replaced.   
  The table below lists the control device associated with a particular function: 
Table 12-8: 
Relay Board Control Devices 
FUNCTION 
CONTROL 
DEVICE 
IN SOCKET 
Wheel Heater 
K1 
Yes 
Bench Heater 
K2 
Yes 
Spare AC Control 
K3 
Yes 
IZS Valves 
U4 
Yes 
IR Source Drive 
U5 
No 
The IR source drive output can be verified by measuring the voltage at J16 with the IR 
source disconnected.  It should be 11.5± 0.5 VDC. 
06864B DCN6314