Service manual

LUMISCAN ACR-2000 READER SERVICE MANUAL - SECTION 5.0 SERVICE ADJUSTMENTS
5-7
5.3.20 Preliminary Scan Adjustment Method A
5.3.20.1 Using an ohmmeter, adjust the following potentiometers to the values listed in the chart. For
orientation, observe the PCA’s so that the PCB writing is from left to right.
Galvo PCA Ohmmeter Connection Potentiometer Value
Top pin of TP1 to left side of R25 R98 240 Ohms
Top of R42 to bottom pin of any test point R47 2.6K Ohms
Top of R40 to bottom pin of any test point R111 550 Ohms
Left side of R34 to top of R41 R45 26K Ohms
Top of R26 to bottom of R27 R23 500 Ohms
DACQ PCA Ohmmeter Connection Potentiometer Value
Right side of R81 to left side of R79 R58 14K Ohms
5.3.20.2 The room lights should be dim and the unit covered to minimize stray light.
5.3.20.3 Place the 14” Linearity Adjust Pattern (P/N 0070-966) in the input slot with the vertical lines
facing the unit and the widest red bar towards the abort button.
5.3.20.4 From the “tools” directory, enter LNADJDT /D at the command prompt. Enter the Serial
Number of the reader. Press <Enter> to continue. When prompted for Lines to Skip, press <Enter>.
When prompted for Black / White Threshold, enter 1200.
5.3.20.5 Use R59 to adjust the Sum of Deltas to nominal.
5.3.20.6 Proceed to 5.3.10.
5.3.21 Preliminary Scan Adjustment Method B
5.3.21.1 Run DDT, Option 10.
5.3.21.2 While observing the laser sweep, adjust Galvo Span and Galvo Offset so that the ends of the laser
sweep extend 1.5 +/- 0.5 inches past the light Collection Chamber opening on the left side and 2.5 +/- 0.5
inches past the light Collection Chamber opening on the right side.
5.3.21.3 Connect oscilloscope trigger sync. channel to TP8 (“SOS”) on the DACQ PCA. Trigger on -Slope
and set sweep to 1 ms/div. Connect channel 1 to TP7 (Galvo Feedback) on the Galvo PCA.
5.3.21.4 On CH1 a downward ramp will be displayed. The shorter upward ramp is the retrace. Use only R45
and R47 make the downward slope to be as straight as possible. This is done by maximizing the peak to peak
voltage without allowing any right facing curvature of the downward slope. Increasing the peak to peak too
much with R45 will cause right facing curvature near the middle of the downward slope. Increasing the peak
to peak too much with R47 will cause right facing curvature near the top of the downward slope.