1.3 No sound
1) No audio signal output to the AV input circuit
Check the audio signal at pins 1 and 13 pins (CG1), 5 and 14 pins (CG2), 2 and 12
pins (VIDEO) of IC5011 of the AV unit.
Check IC5011 and its peripheral circuits.
2) Input mode switching error
Check the AUDIO_SW1/AUDIO_SW2 switching signal at pins 9 and 10 of IC5011. The
switching signal is output from pins 4 and 5 of IC1801. See the table below for input
mode switching.
3) No audio signal output to the speaker
Check the audio signal at pins 3 and 4, 1 and 2 of K16U of the drive unit.
Check the MUTE signal at pin 8 of K16R/K8T.
The MUTE signal is output from pin 48 of IC1801.
Mute ON: High
Check the MUTE signal at pins 3 and 4 of IC1652.
Check the VOLUME signal at pin 7 of K16R/K8T.
The VOLUME signal is output from pin 15 of IC212 and controlled by IC801 through
the IC bus.
Volume minimum: Low
Check the audio signal at IC1651, IC1631 and IC1632 and peripheral circuits.
4) No power to the audio circuit
Check the 6V power supply (6V AUDIO).
Part 4: Troubleshooting
4-7
IC1652
AUDIO
CONTROL
IC1651
PRE.AMP
IC1632
R-AMP.
IC1631
L-AMP.
IC5011
AUDIO-SW
5
14
1
13
2
12
9
10
3
13
PC_L/R
PC_L/R
AV_L/R
Q5008
Q5007
VOLUME
SCL/SDA
A_MUTE
A_SW1
A_SW2
AU_SW2
L
AU_SW1
R
L
R
L
R
5
55
14
17
14
17
7
10
15
1
7
2
6
2
IC1801
I/O
EXPANDER
5
4
IC212
D/A
15
3
2
49
IC801
MAIN
CPU
COMPUTER2
AUDIO IN
COMPUTER1
AUDIO IN
VIDEO
AUDIO IN
3
7
8
1
3
4
1
2
K10T
K16S
K16R
K8T
41
42
39
40
K10Q
K8B
K16U
AV BOARD
M DRIVE BOARD
MAIN BOARD
MUTE On: H
12
3,14
SPEAKERS
29, 30
Fig. 4-3
IC5011 truth table
Pin 10
Pin 9
Mode
L
L
COMPUTER 1
H
L
COMPUTER 2
L
H
VIDEO
Summary of Contents for LV-7545U
Page 2: ...CANON Power Projector LV 7545E D78 5231 SERVICE SMANUAL ...
Page 9: ......
Page 10: ...Part 1 General Information ...
Page 24: ......
Page 25: ...Part 2 Repair Information ...
Page 46: ...Part 3 Adjustment ...
Page 69: ...Part 4 Troubleshooting ...
Page 86: ...Part 4 Troubleshooting 4 17 BH3540 Volume Control IC1652 CXA2101AQ RGB Matrix IC4101 ...
Page 90: ...Part 4 Troubleshooting 4 21 LB1645 Motor Drive IC1601 LC863316 SUB CPU IC1851 ...
Page 91: ...Part 4 Troubleshooting 4 22 ML60851 USB I F IC9801 M62393 D A IC212 IC2381 ...
Page 93: ...Part 4 Troubleshooting 4 24 SII161ACT DVI I F IC8001 STR Z2156 Power Switching IC651 ...
Page 94: ...Part 4 Troubleshooting 4 25 TA1287 RGB YUV Converter IC4551 TB1274AF Video Decoder IC1101 ...
Page 95: ...Part 4 Troubleshooting 4 26 TDA7056 Audio Output IC1631 IC1632 ...
Page 96: ...Part 5 Parts Catalog ...
Page 97: ......
Page 113: ...Part 6 Electrical Diagrams ...
Page 130: ......