Canon LV-7545U, Service Manual

Page: 77 / 130

1.4 Lens Motor Error
1) No drive signal to the motor
Check that the drive signal is observed at pins 1 and 2 of K16M (for focus motor) of the
power supply unit, pins 3 and 4 of K16M (for the zoom motor) and 1 and 2 pins of
K16L (for the lens shift motor).
Check that the drive signal is observed at pins 2 and 10 of IC1611, IC1602 and
IC1601 of the drive IC IC1611, IC1602, and IC1601.
Check IC1611, IC1602, IC1601 and peripheral circuits. Check the motor power
supply (9VA).
2) No drive signal to the motor drive IC
Check that the drive signals are observed at pins 5 and 6 of the drive IC IC1611,
IC1602 and IC1601. The signals are supplied from pins 4 and 5 (focus), pins 6 and
7(zoom) and pins 9 and 10 (lens shift) of D/A control IC, IC1641.
3) No drive signal output from the CPU
The motor drive signal is supplied from the main CPU IC801 through the IC bus.
4) No key switch signal applied to the CPU
A control signal (voltage) is supplied to pins 118 to 120 of IC801 when a control key
switch is pressed.
Part 4: Troubleshooting
4-8
IC1611/IC1602/IC1601 truth table
Input Output Operation
5 6 10 2
H L L H Forward rotation
L H H L Reverse rotation
H H L L Stop
L L - - Standby
10
2
30
29
7
9
10
6
5 118
119
120
6
2
3
IC1602
ZOOM
MOTOR DRIVE
IC801
MAIN CPU
10
2
5
6
1
3
3
4
IC1601
LENS SHIFT
MOTOR DRIVE
CONNECT
BOARD
M
M
ZOOM
MOTOR
LENS SHIFT
MOTOR
K16L
5
4
K8T K16R
K9A
K9B
K9C
K8J
K8S
K68A
CONTROL BOARD
MAIN BOARD
DRIVE BOARD
FOCUS +
FOCUS -
LENS +
LENS -
ZOOM +
SCL
SDA
ZOOM -
TOP_DET.
CENTER_DET.
9 8 7
9 8 7
FOCUS
ZOOM LEVEL +
LEVEL -
10
2 5
4
5
6
1
2
IC1611
FOCUS
MOTOR DRIVE
IC1641
D/A
MOTOR CONTROL
M
FOCUS
MOTOR
K16M
1 3
IC1801
I/O
EXPANDER
13 14
Fig. 4-4