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083730400A DCN8130
Teledyne API – Model T400 O
3
Analyzer
119
5.7.4.2 I
2
C BUS WATCHDOG STATUS LED
The most important of the Relay Board Status LEDs is D1, which indicates the health of
the I
2
C bus. LEDs that remain continuously off or on (not blinking) indicate a fault state
for their respective components.
Table 5-5. Relay PCA Watchdog LED Failure Indication
LED
FUNCTION
FAULT STATUS
INDICATED FAILURE(S)
D1
(Red)
I
2
C bus Health
(Watchdog
Circuit)
Continuously ON or
Continuously OFF
Failed/Halted CPU
Faulty Motherboard, Valve Driver board or Relay PCA
Faulty connectors/wiring between Motherboard, Valve Driver board
or Relay PCA
Failed/5 VDC Power Supply (PS1)
5.7.4.3 O
3
OPTION STATUS LED
Figure 5-12. Relay PCA Status LEDs Used for Troubleshooting