Teledyne GFC-7001E - Trace CO Analyzer User Manual
Page 275
Troubleshooting & Repair
Model GFC7001E Carbon Dioxide Analyzer
Teledyne Analytical Instruments
275
13.1.4.2. Sync Demodulator Status LED’s
Two LED’s located on the Sync/Demod Board and are there to make it obvious that the GFC Wheel is spinning 
and the synchronization signals are present: 
Table 13-3: Sync/Demod Board Status Failure Indications
LED
FUNCTION
FAULT STATUS
INDICATED FAILURE(S)
D1
M/R Sensor Status
(Flashes slowly)
LED is stuck
ON or OFF
GFC Wheel is not turning 
M/R Sensor on Opto-Pickup Board failed 
Sync/Demod Board failed 
JP 4 Connector/Wiring faulty 
Failed/Faulty +5 VDC Power Supply (PS1) 
D2
Segment Sensor
Status
(Flashes quickly)
LED is stuck
ON or OFF
GFC Wheel is not turning 
Segment Sensor on Opto-Pickup Board failed 
Sync/Demod Board failed 
JP 4 Connector/Wiring faulty 
Failed/Faulty +5 VDC Power Supply (PS1) 
D1 – M/R Sensor Status
D2 – Segment Sensor Status
JP4 Connector to Opto-Pickup
Board
Figure 13-4:
Sync/Demod Board Status LED Locations