Thermo Scientific 410i Instruction Manual page 193

Thermo Fisher Scientific
1. Turn the instrument OFF, unplug the power cord, and remove the
cover.
2. Disconnect the cable from the PREAMP connector on the
measurement interface board and disconnect the two wires from the
top of the chopper motor plate.
3. Remove the two screws holding the preamplifier cover to the
preamplifier assembly and remove the cover.
4. Insert an Allen wrench through the access holes in the preamplifier
printed circuit board, and remove the screws holding the detector
assembly to the optical bench. Carefully remove the detector assembly
from the optical bench.
5. Install the new detector assembly by following the previous steps in
reverse.
6. Calibrate the preamp board, and then return to Step 7 to set S/R. Refer
to the "Preamp Board
7. Set S/R as follows:
a. From the Main Menu, choose Service > Initial S/R Ratio.
The Initial S/R Ratio screen appears.
b. At the Initial S/R Ratio screen, press
S/R ratio to the value of the current ratio and press to store the
value. The initial S/R ratio should be between 0.800 and 1.20.
Note If Service Mode is not displayed, refer to
Mode" on page 7-4, then return to the beginning of this step.
8. Calibrate the instrument. Refer to the "Calibration" chapter in this
manual.
Detector/Preamplifier Assembly Replacement
Calibration" procedure that follows.
"Accessing the Service
Model 410i Instruction Manual
Servicing
to select set the initial
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7-21