Sanyo PLC-SU25, Service Manual

Page: 45 / 105

-45-
Lens Motor Problems
Troubleshooting
No Sound
Logic Table of IC5501/IC5551
Input Output Operation
4 5 7 1
H L L H Forward drive
L H H L Reverse drive
H H L L Braking
L L - - Stand by
Check PC/AV-audio switching circuit.
Check IC001, audio-sw IC, and peripheral circuit. PC/AV_SW5
(PC:L) signal is applied on pin 10 of IC001 through Q041.
MUTE5 signal (Mute:H) is applied on pin 9 of IC001 output from
pin 12 of IC1803
through IC1351, buffer IC.
Is the audio signal
observed on the AUDIO-
OUT terminal?
Check Audio amp.and control circuit.
Check IC5001, audio-amp IC, and peripheral circuit. MUTE5
signal (Mute:L) is applied on pin 1 of IC5001, output from pin 12
of IC1803
through IC1351, buffer IC. VOL_CTL signal is applied on pin
4 for volume control, sent from pin 19 of IC3561.
Is the audio signal
observed on pin 6 of
IC5001?
Check audio output circuit.
Check speaker, connection of the terminals “K10T”, “K8F”.
Yes
No
Yes
No
Check the power supply (7VMCI) circuit, IC5501 and IC5551 and
peripheral circuit. Check Key SW board.
Both of ZOOM and
FOCUS motors are not
functioning.
No
Yes
Check the ZOOM motor control circuit.
Zoom motor is controlled by signal ZOOM +, - output from pins
1 and 7 of IC5501. These control signals are driven by IC301,
system control IC, and applied to pins 4 and 5 of IC5501 through
the IC1804, I/O-sw IC.
Only ZOOM motor is not
functioning.
No
Yes
Check the FOCUS motor control circuit.
Focus motor is controlled by signal FOCUS +, - output from pins
1 and 7 of IC5551. These control signals are driven by IC301,
system control IC, and applied to pins 4 and 5 of IC5551 through
the IC7801, D/A IC.
Only FOCUS motor is
not functioning.
No
Yes
Check logic table of motor
drive ICs, IC5501, IC5551.
Check following steps.
Check following steps.