Fluke Biomedical 945A - Manual (Page 42)

Preamplifier/UDR Diagnostic LED Indicators
977-210 Detector/Preamplifier
The LEDs listed below are located on the 977-210-10 Communication/Interface board. This is the larger
of the two circuit boards in the detector assembly.
Designator
Function / Status Indicated
LED 1 +15 VDC is being supplied to the detector from the
UDR when ON
LED 2 ON (bright): both + 15 and -15 volt loops present
ON (dim): Only one loop supply present
OFF: no loop voltage from either supply
LED 4 HV is being generated when LED is ON. No HV
supply when LED is OFF
LED 5 +12 VDC is being supplied to the HV driver when
LED is ON.
+12 VDC is not present to the HV driver when LED
is OFF
NOTE: There is no LED 3 installed on the circuit board
946A-200 UDR
The sole diagnostic LED in the UDR is CR10, located on the 942-200-80 Communications Interface
Board. When CR10 is ON (bright), both the +15 and -15 loop voltages are present at receive. A dim
CR10 indicates only one supply is present. CR10 is OFF indicates that no loop supplies are present at
the receive terminal.
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