Replacing The Fid Signal Board - Agilent Technologies 7820A Service Manual

Agilent 7820 GC Service
53

Replacing the FID signal board

1 Cool down the oven.
Turn off the GC main power switch and disconnect its power
cord.
Hazardous voltages are present in the
mainframe when the GC power cord is connected.
Avoid a potentially dangerous shock hazard by
disconnecting the power cord before removing
any GC panels.
Components can be damaged by static electricity:
be sure to wear an ESD strap grounded to the GC
chassis while performing this procedure.
Turn off all gas flows at their sources.
Inlets, detectors, and the oven are insulated
with fibrous materials which may cause
irritation to skin, eyes, and/or mucous
membranes. Always wear gloves when working
with the insulation.
insulation is flaky/crumbly, wear protective
eyewear and a suitable breathing mask and/or
respirator.
Remove the right side electronics panel from the GC.
Lift up the GC detector cover to access the FID.
Disconnect all electrical connections between the FID and the
signal board.
Rotate the FID board thumbscrew counterclockwise, lift the
board up and then downward to remove it from the GC.
Replace the defective board with a new FID board.
Restore the FID electrical connections.
Reassembly is the reverse of these steps.
Reconfigure the GC using the software keypad, supplying the
Additionally, if the