Canon EOS 20D Service Manual page 147

Adjustments
<Adjustment Procedure>
1) When replacing IMG Unit (Same front panel unit is used continuously)
Note: Service parts are set to 43.10mm at the factory, and their image units are adjusted.
Each offset data is attached to the parts. Therefore, based on the 43.10mm
standard, the offset needs to be added or subtracted to calculate the final distance.
Then, finally select washer that meet calculated distance.
Washer Calculation Procedure:
(1) Ex: Offset values of the replacement parts
Upper Left: -0.069
Upper Right: 0.02
Bottom: 0.051
(2) Measure the distance between the mount plane
and the CMOS mounting washer planes.
Upper Left: 42.97mm
Upper Right: 42.96mm
Bottom: 42.93mm
(3) Calculate the washer offset values.
Upper Left: 43.10-0.069-42.97=0.06mm (LW)
Upper Right: 43.10+0.020-42.96=0.16mm (RW)
Bottom: 43.10+0.051-42.93=0.22mm (BW)
(4) Attach the washer. (Do not glue)
CB3-0060-000 (XXX)
4
Fig. 004
Fig. 005
RW
LW
BW
Fig. 006
A ± 0.015 SIZE
0.03 mm (003)
A
0.05 mm (005)
0.08 mm (008)
0.10 mm (010)
0.12 mm (012)
0.15 mm (015)
0.18 mm (018)
0.20 mm (020)
Fig. 007