Teledyne T360 Carbon Monoxide Alarm User Manual


 
Troubleshooting and Service Teledyne API Model T360/T360M Operation Manual
248
A voltmeter should be used to verify that the DC voltages are correct per the
values in the table below, and an oscilloscope, in AC mode, with band limiting
turned on, can be used to evaluate if the supplies are producing excessive noise
(> 100 mV p-p).
Table 8-7: DC Power Supply Acceptable Levels
CHECK RELAY BOARD TEST POINTS
FROM TEST POINT TO TEST POINT
POWER
SUPPLY
ASSY
V
OLTAGE
NAME # NAME #
MIN V MAX V
PS1 +5 Dgnd 1 +5 2 4.8 5.25
PS1 +15 Agnd 3 +15 4 13.5 16V
PS1 -15 Agnd 3 -15V 5 -14V -16V
PS1 Agnd Agnd 3 Dgnd 1 -0.05 0.05
PS1 Chassis Dgnd 1 Chassis N/A -0.05 0.05
PS2 +12 +12V Ret 6 +12V 7 11.75 12.5
PS2 Dgnd +12V Ret 6 Dgnd 1 -0.05 0.05
8.5.3. I
2
C Bus
Operation of the I
2
C 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 I
2
C 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 I
2
C bus if both D1 on the relay PCA and D2 of
the Valve Driver PCA are ON/OFF constantly (steady lit or steady off)
8.5.4. 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.
07272B DCN6552