Canon A-1 Repair Manual page 77

6. W hen their IC is replaced the R OSC and R ADNUL must be
correctly adjusted. The adjustment is different from the
AE-l adjustment and it has a direct effect on the
viewfinder display . (See Section 4, IC Replacement) .
7. The flexible circuits used in the A-I are high densitity
with patterns on both sides. Jumper wires cannot be
used. Care should be taken not to crimp or break the
pattern when installing the top cover.
8 . Certain voltages and signals are basic . They are El
(Suppl y voltage) for each IC, CLK (clock pulse) SYNC (07)
(the synchronization trigger), I. BUS (input busline) and
O. BUS (output busline).
9 . In order to understand the A-I circuit, it is necessary
to study the detail operation of each IC as outlined in
section 3 o f this repair guide.
10 . The A- I is a s y stem camera . It uses the following major
accessories : POWER WINDER A, MOTOR DRIVE MA, SPEEDLITES
l55A and 199A, DATA BACK A and WIRELESS CONTROLLED LC-l
as we ll as all the FD lenses and other abcessories.
Operation wi t h the v a r i o u s accessories must be cons i dered
whe n repairing the basic camera.
11 . Since the mechanical design is similar to the AE-l, the
common repair operations ha v e not been included in this
guide . Refer to the AE-l Repair Guide .
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