Sony LLC-8000A User manual

LL CONTROL CONSOLE
LLC-8000A
SERVICE MANUAL
1st Edition
STUDENT EXPANSION BOARD
LU-816A
LL CONFERENCE BOARD
LU-800B
LL CONFERENCE BOARD
LU-801B
This service manual does not show some of the items that
are common to the model LLC-8000. Therefore, use this
Service Manual together with the LLC-8000 Service Manual
(9-977-680-01).
Printed in Japan
Sony Corporation 1999. 6 16
Broadcasting & Professional Systems Company ©1999
LLC-8000A
LU-800B
LU-801B
LU-816A (SY) E
9-955-172-01

The material contained in this manual consists of
information that is the property of Sony Corporation.
Sony Corporation expressly prohibits the duplication of
any portion of this manual or the use thereof for any
purpose other than the operation or maintenance of the
equipment described in this manual without the express
written permission of Sony Corporation.
Le matériel contenu dans ce manuel consiste en
informations qui sont la propriété de Sony Corporation.
Sony Corporation interdit formellement la copie de
quelque partie que ce soit de ce manuel ou son emploi
pour tout autre but que des opérations ou entretiens de
l’équipement à moins d’une permission écrite de Sony
Corporation.
Das in dieser Anleitung enthaltene Material besteht aus
Informationen, die Eigentum der Sony Corporation sind.
Die Sony Corporation untersagt ausdrücklich die
Vervielfältigung jeglicher Teile dieser Anleitung oder den
Gebrauch derselben für irgendeinen anderen Zweck als
die Bedienung oder Wartung der in dieser Anleitung
beschriebenen Ausrüstung ohne ausdrückliche
schriftliche Erlaubnis der Sony Corporation.

1
LLC-8000A
Table of Contents
1. Service Overview
1-1. Relative Manuals.........................................................................................1-1
1-2. Main Changes Made from LLC-8000 System to LLC-8000A System ......1-1
2. Self-Diagnosis
2-1. CPU-240 Board ...........................................................................................2-1
2-1-1. POWER ON Indicator................................................................2-1
2-1-2. Self-diagnosis of the CPU-240 Board ........................................2-2
2-2. Operation Unit.............................................................................................2-5
2-3. ASW-58 Board (LU-800B/LU-801B) ........................................................2-6
2-3-1. LED Indicators When the Main Power Is Turned On................2-6
2-3-2. Self-diagnosis of the ASW-58 Board.........................................2-7
2-3-3. Troubleshooting the ASW-58 Board (LU-800B/LU-801B) ....2-12
3. Semiconductor Pin Assignments
4. Spare Parts
4-1. Notes on Repair Parts..................................................................................4-1
4-2. Exploded Views ..........................................................................................4-2
4-3. Electrical Parts List .....................................................................................4-8
4-4. Packing Materials......................................................................................4-36
5. Circuit Description and Block Diagrams
5-1. Signal Flow in LLC-8000A System............................................................5-1
5-2. Circuit Description ......................................................................................5-1
5-3. Block Diagrams...........................................................................................5-2
5-3-1. Audio..........................................................................................5-2
5-3-2. Audio (ASW-58 Board) .............................................................5-4
5-3-3. DC Power ...................................................................................5-7
5-3-4. ASW-58 Digital Signal ..............................................................5-8
5-3-5. Random Pair and Group Conference Control ..........................5-10

2LLC-8000A
6. Analog Signal Flow
6-1. Standard Type .............................................................................................6-2
6-2. Add-in Type 1 .............................................................................................6-4
6-3. Add-in Type 2 .............................................................................................6-6
6-4. Add-in Type 3 .............................................................................................6-8
7. Schematic Diagrams and Board Layouts
Frame ......................................................................................................................7-3
ASW-58 ............................................................................................................7-4, 16
CPU-240 .........................................................................................................7-10, 18
IF-645A ..........................................................................................................7-12, 20
CN-1810 .........................................................................................................7-13, 19
LED-288 ...............................................................................................................7-14

1-1
LLC-8000A
Section 1
Service Overview
This section describes only the differences between the LLC-8000A and LLC-8000. Therefore, read
Section “3. Service Overview” of the LLC-8000 Service Manual (9-977-680-01) together with this
manual.
1-1. Relative Manuals
Beside this “LLC-8000A Service Manual”, the following manuals are available for LLC-8000A System.
.Operation Manual LLC-8000A 3-866-264-11 (E)
3-866-264-21 (F)
3-866-264-31 (S)
3-866-264-41 (I)
ER-8020 3-858-847-11 (E)
3-855-847-21 (F)
3-855-847-31 (S)
PTU-8 3-859-429-11
.Getting Started Guide MLS-8000A 3-866-424-11
.Installation Manual LLC-8000A 3-202-126-11
MLS-8000A 3-202-337-01
LU-800B/801B 3-202-118-11
.Service Manual LLC-8000 9-977-680-01
ER-8020 9-977-681-01
EA-80 9-955-136-01
PTU-8 9-977-682-01
1-2. Main Changes Made from LLC-8000 System to LLC-8000A System
.The IF-645 board is replaced by the IF-645A board.
.The CN-1810 board is newly added.
.The optional board (ASW-58) is newly added. (LU-800B, LU-801B)

2-1
LLC-8000A
Section 2
Self-Diagnosis
The self-diagnosis helps troubleshooting and field-servicing.
The self-diagnosis software of the LLC-8000A consists of the following programs.
.Self-diagnosis of the CPU-240 board
.Self-diagnosis of the Operation Unit
.Self-diagnosis of the ASW-58 board (LU-800B/LU-801B)
2-1. CPU-240 Board
2-1-1. POWER ON Indicator
The LED’s on the CPU-240 board are illuminated, as follows:
D1 : CPU Run indicator
Flashes in red when CPU main routine works as intended.
D2 : +5 V power supply indicator
Lights in green when the voltage of +5 V is provided.
D18 : Power key input LED
Lights in red when the power key of the operation unit is pressed.
D19 : Signal transmission system indicator
Lights in red when signal transmission system works as intended for the number of students that
are registered on installation setting stage.
CPU-240 Board
CPU
IC60
NORM DIAG
S1
D19 D18 D1 D2
+5 V Power supply indicator (green)
CPU run indicator (red)
Power key input LED (red)
Signal transimission system indicator (red)

2-2 LLC-8000A
2-1-2. Self-diagnosis of the CPU-240 Board
Remove the CPU-240 board with the main power off. Exchange IC43 with the self-diagnosis ROM.
Connect the checker tool. Set the switch S1 to the DIAG position. Then turn on the main power.
The self-diagnosis software of the CPU-240 board starts up.
n
Self-diagnosis ROM (Servicing use only)
IC M27C512-C8000AV110 : 8-759-588-82
Checker
Fabricate the checker tool as shown below for troubleshooting and field-servicing the CPU-240 board.
2-1. Self-Diagnosis of the CPU-240 Board
1
2
3
4
5
6
7
8
10
9
11
12
13
14
1
TXB5
T5
CN5
RXB5
23456
10121314 9 811
+5V
V
DD
GND
74HC00
7
O1
O2
O3
O4
O5
O6
O7
O8
O9
O10
O11
O12
O13
O14
O15
O16
O17
O18
O19
O20
O21
O22
O23
O24
O25
O26
O27
O28
O29
O30
O31
O32
O33
O34
O35
O36
O37
O38
O39
O40
CN1
O1
O2
O3
O4
O5
O6
O7
O8
O9
O10
O11
O12
O13
O14
O15
O16
O17
O18
O19
O20
O21
O22
O23
O24
O25
O26
O27
O28
O29
O30
O31
O32
O33
O34
O35
O36
O37
O38
O39
O40
CN2
O1
O2
O3
O4
O5
O6
O7
O8
O9
O10
O11
O12
O13
O14
O15
O16
O17
O18
O19
O20
O21
O22
O23
O24
O25
O26
O27
O28
O29
O30
O31
O32
O33
O34
O35
O36
O37
O38
O39
O40
CN3
O1
O2
O3
O4
O5
O6
O7
O8
O9
O10
O11
O12
O13
O14
O15
O16
O17
O18
O19
O20
O21
O22
O23
O24
O25
O26
O27
O28
O29
O30
O31
O32
O33
O34
O35
O36
O37
O38
O39
O40
CN4
TXB3
RXB3
TXB4
RXB4
TXB2
RXB2
TXB1
RXB1
O13
O25
O12
O24
O11
O23
O10
O22
O9
O21
O8
O20
O7
O19
O6
O18
O5
O17
O4
O16
O3
O15
O2
O14
O1
CN6
KD2
KD1
KD0
KD3
AS3
AS5
AS2
AS0
AS1
DS0
PCSEL1
AS6
AS7
AS4
T2
T1
T4
T0
T3
1
2
3
4
5
6
7
8
9
10
11
12
13
14
CN7
10K
10K
10K
10K
+5V
KD3
KD2
KD1
KD0
T4
T3
T2
T1
T0
b8
b7
b6
b5
b4
b3
b2
b1
b0
+6V
b8
b7
b6
b5
b4
b3
b2
b1
b0
b9
DS0
AS7
AS6
AS5
AS4
AS3
AS2
AS1
AS0
PCSEL1
+5V
+5V
GND
A+5V
GND
+12V
AGND
_12V
+6V
_6V
+15V

2-3
LLC-8000A
Connection
2-1. Self-Diagnosis of the CPU-240 Board
Exchange IC43 with the self-diagnosis ROM.
CN1
CN2
CN3
CN4
CN5 S1
NORM DIAG ROM
IC43
CN8 CN6
CN7
CPU-240 Board
1
2
3
4
5
6
7
8
9
DTR
DCD
RXD
RTS
TXD
CTS
POWER +5 V
±6 V
±12 V
±15 V
Connect cable Connect cable
Shorting
Connector
CPU-240 Board Checker
CN8
9P.D-SUB connector
Shorting connector
CN7 CN7
Connect cable
Connect cable
Connect cable
Connect cable
Connect cable
25P.D-SUB connector
CN1
CN2
CN3
CN4
CN5
CN6
CN8
CN1
CN2
CN3
CN4
CN5
CN6

2-4 LLC-8000A
Operation
Servicing on the CPU-240 digital control system is performed with the nine (9) key switches and ten (10)
LED’s, while that on the CPU-240 audio system is done with the CPU-240 board built into the control unit.
First set the key switches, as shown in Section Key Data, according to the check mode, and turn the
power switch on. Refer to Section LED Display and perform the servicing. The self-diagnosis software
begins to work in the selected check mode right after the power switch is turned on.
Perform the digital overall check first and locate systems in which troubles are supposed to be involved.
Be sure to turn off and on the power switch or reset the CPU when the check mode is switched.
Key Data
No. b8 b7 b6 b5 b4 b3 b2 b1 b0 HEX Check Mode
KD3 KD2 KD1 KD0 T4 T3 T2 T1 T0 CODE
1000100000020Digital overall check
(No.2 to 11 once)
2000100001021ROM check (once)
3000100010022RAM check (repeat)
4000100100024NV-RAM check (once)
5000101000028ICMemory check (once)
6001000001041SIO CN1 check (repeat)
7001000010042SIO CN2 check (repeat)
8001000100044SIO CN3 check (repeat)
9001001000048SIO CN4 check (repeat)
10001010000050SIO RS232C check (repeat)
1100101111105FSIO CN5 check (repeat)
No. b9 b8 b7 b6 b5 b4 b3 b2 b1 b0 Check Mode
PCSEL1 DS0 AS7 AS6 AS5 AS4 AS3 AS2 AS1 AS0
1 ROM RAM NU-RAM IC MEN SIO OFF RS232C OFF OFF OFF Digital overall check (once)
OK OK OK OK OK 1 OK 1 1 1
2 CHECK OFF OFF ON OFF OFF OFF OFF OFF ON ROM check (once)
OK110111110
3 CHECK OFF OFF ON OFF OFF OFF OFF ON OFF RAM check (repeat)
OK110111101
4 CHECK OFF OFF ON OFF OFF OFF ON OFF OFF NV-RAM check (once)
OK110111011
5 CHECK OFF OFF ON OFF OFF ON OFF OFF OFF IC Memory check (once)
OK110110111
6 CHECK OFF ON OFF OFF OFF OFF OFF OFF ON SIO CN1 check (repeat)
OK101111110
7 CHECK OFF ON OFF OFF OFF OFF OFF ON OFF SIO CN2 check (repeat)
OK101111101
8 CHECK OFF ON OFF OFF OFF OFF ON OFF OFF SIO CN3 check (repeat)
OK101111011
9 CHECK OFF ON OFF OFF OFF ON OFF OFF OFF SIO CN4 check (repeat)
OK101110111
10 CHECK OFF ON OFF OFF ON OFF OFF OFF OFF SIO RS232C check (repeat)
OK101101111
11 CHECK OFF ON OFF ON OFF OFF OFF OFF ON SIO CN5 check (repeat)
OK101011110
LED Display
LED
1. CHECK OK : LED ON
2. ON : LED ON
3. OFF : LED OFF
2-1. Self-Diagnosis of the CPU-240 Board

2-5
LLC-8000A
2-2. Operation Unit
.While pressing the
MODEL
key, press the
POWER
key simultaneously. This action makes the 7-segment
LED indicate 888, initiating the self-diagnosis software to work.
.Pressing the
DISPLAY
MODE
key makes the 7-segment LED indicate 01, and each of the keys then becomes
ready to illuminate LED’s, as follows:
The monitor key illuminates its LED in red, green, and turns it off, alternately.
The keys with no built-in LED illuminate nearby LED’s, as shown in the chart.
Key LED
SCANNING MONITOR INDIVIDUAL
1 STUDENT RECORDER MODE º
2 STUDENT RECORDER MODE π
3 STUDENT RECORDER MODE ‚
4 STUDENT RECORDER MODE ‚
5 STUDENT RECORDER MODE RECORD
CALL CLEAR NUMBER OF ANSWER
FEED BACK RESPONSE RATIO
IC MEMORY 0QUESTION NUMBER
ALL MEMORY TIME
IC MEMORY )PROGRAM NUMBER
.On the student remote control panel, pressing the pkey turns off LED’s for 0, ”, )and
RECORD
keys.
.Another pressing the
DISPLAY
MODE
key makes the 7-segment LED indicate 02, and all the LED’s for the
monitor keys illuminate simultaneously.
POWER
ATTEND
CALL
CLEAR
COPY
x2
PROGRAM
1→2
PAIR
MODEL
CONFERENCE
COMMUNICATION
VIDEO
1
VIDEO
2
MONITOR TV ROOM TV SPEAKER STUDENT RECORDER MODE
PROGRAM CONTROL
IC MEMORY
STUDENTS REMOTE CONTROL
PATTERN
VIDEO VIDEO
1
VIDEO
2VIDEO MONITOR ROOM
ANALYZER START/
CLOSE
DISPLAY
MODE FEED BACK
DATA SET MEMORY
SELECT
12345
PROGRAM
1
PROGRAM
2
PROGRAM
3
PROGRAM
4LIBRARY ASSIGN
ALL
INDIVIDUAL
LID LOCK
MIC CUT
x1
AUTO
TRANSFER
x2
AUTO
TRANSFER AUTO TEST
RECORD
REPEAT
PLAY MONITOR
RECORD
PROGRAM
CUT
MIC MIX
INTERCOM ALL CALL
SCANNING
MONITOR
LL CONTROL CONSOLE LLC-8000A
-20 -8 -5 -3 0 3 8 +dB
AUDIO LEVEL
MEMORY TIME
PROGRAM NUMBER
NUMBER OF
ANSWERS
RESPONSE RATIO
QUESTION
NUMBER
AA
AA
AA
AA
A
A
A
A
A
A
A
A
A
A
AA
AA
AA
AA
A
AA
AA
AA
AA
AA
AA
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
AA
AA
AA
AA
A
A
A
AA
AA
AA
AA
A
A
A
AA
AA
AA
AA
A
A
A
A
A
A
A
A
A
A
A
A
A
A
AA
AA
AA
AA
A
AA
AA
AA
AA
AA
AA
AA
AA
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
AA
AA
AA
AA
A
A
A
A
A
AA
AA
AA
AA
A
A
A
A
A
Monitor key
2-2. Operation Unit

2-6 LLC-8000A
2-3. ASW-58 Board (LU-800B/LU-801B)
2-3-1. LED Indicators When the Main Power Is Turned On
The LEDs on the ASW-58 board are illuminated as follows:
D1 : +5 V Power supply indicator
Turns on in green when the +5 V power voltage is supplied.
D2 : CPU run indicator
Flashes when the CPU main routine works as intended.
D3 : Self-diagnosis indicator
Turns on when the Self-diagnosis program of the ASW-58 board works.
Turns off during the normal operation.
D4 : Normal operation indicator
Turns on to indicate that the software works normally in LU-800B or LU-801B.
LU-800B : Turns on
LU-801B : Turns off
2-3. Self-diagnosis of the ASW-58 Board (LU-800B/LU-801B)
CN7
D1 D2 D3
D4
CN5
S1
ASW-58 Board
Normal operation indicator (red)
Self-diagnosis indicator (red)
CPU run indicator (red)
+5 V power supply indicator (green)
NORM DIAG

2-7
LLC-8000A
2
1
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
2
3
5
6
8
9
11
12
14
15
17
18
20
21
23
24
26
27
29
30
32
33
35
36
38
39
41
42
44
45
47
48
50
2
3
5
6
8
9
11
12
14
15
17
18
20
21
23
24
26
27
29
30
32
33
35
36
38
39
41
42
44
45
47
48
50
2
3
5
6
8
9
11
12
14
15
17
18
20
21
23
24
26
27
29
30
32
33
35
36
38
39
41
42
44
45
47
48
50
CN1
B1 MONI
B1 MON
B16 MONI
B16 MON
B1 MON
B64 MON
B1 MONI
B64 MONI
B32 MONI
B32 MON B48 MONI B48 MON B64 MONI B64 MON
B17 MONI
B17 MON B33 MONI B33 MON B49 MONI B49 MON
CN2 CN3 CN4
Audio level
meter
DC regulated
powersupply
Oscillator
1kHz
_10dB
1
2
3
+15V
0V
CN7 CN6
1
2
3
4
5
6
7
8
9
10
11
12
SW1
SW2
SW3
SW4
SW5
SW6
SW7
2-3. Self-diagnosis of the ASW-58 Board (LU-800B/LU-801B)
2-3-2. Self-diagnosis of the ASW-58 Board
Remove the ASW-58 board with the main power off. Connect the ASW-58 board to the checker tool.
Set the switch S1 to the DIAG position. Then turn on the main power. The self-diagnosis software of the
ASW-58 board starts.
Checker
Fabricate the checker tool as shown below for troubleshooting and field-servicing the ASW-58 board.

2-8 LLC-8000A
Connection
CN7
S1
ASW-58 Board Checker
CN1
CN3
CN2
CN4
CN6
ASW-58 Board
NORM DIAG
CN1
CN2
CN3
CN4
CN6
CN1
CN2
CN3
CN4
CN6
CN7
Oscillator
Audio level
meter
DC regulated
power supply
2-3. Self-diagnosis of the ASW-58 Board (LU-800B/LU-801B)

2-9
LLC-8000A
4 (sec) 4 (sec)
1(sec)
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON ON
ON
ROM
RAM
RS-232C
ROM +RAM
ROM +232C
RAM +232C
NG
NG
NG
NG
NG
NG
2-3. Self-diagnosis of the ASW-58 Board (LU-800B/LU-801B)
Operation
The digital system is automatically diagnosed when the main power is turned on. Result of the diagnosis
is displayed on the D3 (DIAG) LED on the ASW-58 board. Troubleshoot the digital system from the
display on the D3 (DIAG) LED.
At the same time, the fixed student-pair pattern is formed by the cross-point IC on the respective boards
(LU-800B/LU-801B). The fixed student-pair pattern thus formed, enables to diagnose if the correct gate
is opened by inputting and outputting the audio signal to and from the checker tool.
The LLC-8000A enters the CONFERENCE mode by operating the 7 key switches. The desired fixed
CONF. pattern can be formed by the combination of the 7 key switches as shown below.
When a trouble occurs in the audio system, locate the signal line in which the source of trouble is located,
using the technique of forming the fixed student-pair patterns and the fixed CONF. pattern as described
above.
Digital system check
Check the digital system from illumination of the D3 (DIAG) display.
Check result Illumination of the D3 (DIAG) display
ALL OK Turns on
ALL NG Turns off
ROM NG Blinking once, is repeated
RAM NG Blinking twice, is repeated
RS-232C NG Blinking three times, is repeated
(ROM +RAM) NG Blinking (once +twice), is repeated
(ROM +232C) NG Blinking (once +three times), is repeated
(RAM +232C) NG Blinking (twice +three times), is repeated

2-10 LLC-8000A
Gp No.
Student pair No.
1234
1234
9101112
8
8
16
9
17
25
10
18
26
16
24
32
. . . . .
. . . . .
. . . . .
. . . . . . . . . .
. . . . .
2-3. Self-diagnosis of the ASW-58 Board (LU-800B/LU-801B)
Gp No.
Student pair No.
1234
1234
64 63 62 61
8
8
57
16
16
49
24
24
41
32
32
33
. . . .
. . . .
. . . . . .
. . . . . .
. . . . . . .
. . . . . . .
. . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . .
SW1 SW2 SW3 SW4
SW position CONF. Gp No.
64
students
32
students
16
students
x
x
x
x
x
O
x
O
x
O
x
x
8
students
Oxxx
Students No.
1
1
12
1234
23
5678
4
1 to 4
64 to 61
5 to 8
60 to 57
9 to 12
56 to 53
13 to 16
52 to 49
17 to 20
48 to 45
21 to 24
44 to 41
24 to 28
40 to 37
29 to 32
36 to 33
Audio system check
Fixed student-pair pattern
The following patterns are formed when the switches SW1 to SW7 are turned off.
ASW-58/64 board (LU-801B)
ASW-58/32 board (LU-800B)
Fixed CONF. pattern
The desired patterns are formed by the combination of the switches SW1 to SW4.
(Set SW5 to SW7 to OFF.)
ASW-58/64 board (LU-801B)
ASW-58/32 board (LU-800B)
SW1 SW2 SW3 SW4
SW position CONF Gp No.
32
students
16
students
8
students
x
x
O
x
O
x
O
x
x
NC
NC
NC
Students No.
1
1
1234
2
1 to 4
9 to 12
5 to 8
13 to 16
17 to 20
25 to 28
21 to 24
29 to 33

2-11
LLC-8000A
2-3. Self-diagnosis of the ASW-58 Board (LU-800B/LU-801B)
SW1 SW2 SW3 SW4
SW position CONF. Gp No.
64
students
64
students
64
students
x
x
x
x
x
x
x
x
x
SW5
x
x
O
SW6
x
O
x
SW7
O
x
x
x
x
x
Students No.
25
17
9
1 to 64
Shifting the CONF. Gp
The all student CONF state can be shifted to the CONF state of the specified students by as follows by
setting the switches as shown below.
.ASW-58/64 board (LU-801B)
.ASW-58/32 board (LU-800B)
SW1 SW2 SW3 SW4
SW position CONF. Gp No.
32
students
xxx
SW5
O
SW6
x
SW7
xx
Students No.
9
1 to 32

2-12 LLC-8000A
2-3-3. Troubleshooting the ASW-58 Board (LU-800B/LU-801B)
Outline
The defective area of the ASW-58 board can be located while it is installed in the LLC-8000A control
unit. However, the diagnosis assumes that the LLC-8000A is known to be good (i.e., abnormality occurs
only when “random pair” and/or “group conference are formed).
Tool
Construct the switch tool locally as shown below.
Preparation
1. Confirm that the ASW-58 board is attached to the control unit. Remove the 14-pin harness (between
ASW-58, CN5 ↔CPU-240, CN5).
2. Connect the locally-constructed switch tool to CN6 of the ASW-58 board. Set the slide switch S1 in
the DIAG position then switch on the POWER button of the control unit.
n
Do not use a personal computer (GUI), but operate the control unit from the operation unit (OPU).)
Check
1. Checking the ASW-58 on-board indicators
Check the LED indication of the LEDs D1 to D4. (Refer to Sections “2-3-1. and 2-3-2.)
2. Checking the ASW-58 board voltages
Check the voltage at TP3 to TP6.
TP3 +5 V ±0.2 V
TP4 _5 V ±0.2 V
TP5 +5 V ±0.2 V
TP6 +9 V ±0.4 V
TP7 GND
Gp selection
LU-800B LU-801B
GP1
GP1
GP9 GP9
GP17
GP25
1
2
3
4
5
6
7
8
9
10
11
12
SW3
SW4
SW5
SW6
SW7
2 mm pitch connector
To ASW-58 board (CN6)
2-3. Self-diagnosis of the ASW-58 Board (LU-800B/LU-801B)

2-13
LLC-8000A
IC33
IC1 IC3 IC9 IC11
IC5 IC7 IC13 IC15
IC2 IC4 IC10 IC12
IC6 IC8 IC14 IC16
OUT 1
32
33
64
GP1
IN 1
32
33
64
816917 24 25 32
Audio switch
IC33 to IC54
Tape playback
and MIC of
each student
Monitoring of
each student of
OPU
Cross-point
switch for
mixing inputs
Amplifiers
IC17 to IC32 of
each group
Cross-point
switch for
distributing
the outputs
2-3. Self-diagnosis of the ASW-58 Board (LU-800B/LU-801B)
3. Checking audio signals
.When the check tool of “2-3-2” is used as an oscillator for tape playback and as the MIC signal of
each student while the level meter is used as the student monitor of the OPU, then all items of the
self-diagnosis can be performed. (Refer to the pair pattern table and the conference pattern table.)
.When the “random pair” and/or “group conference” functions cannot be used at all, check the
peripheral circuits and components of the audio switch shown on the simplified audio block
diagram.
.When an abnormality occurs in a specific student, check the parallel connections such as mutual
interconnections between different student booths, on the simplified block diagram.
.When an abnormality occurs in a specific student pair No., or in a specific group No., check the
serial connections on the simplified block diagram.
Simplified Block Diagram
n
The input circuit and the output circuit of the cross-point switches are turned on and off by the same gate.
(IC1 and IC2), (IC3 and IC4), (IC5 and IC6), (IC7 and IC8), (IC9 and IC10), (IC11 and IC12), (IC13 and
IC14), (IC15 and IC16)
D1 D3
ABCD EFGHJKLM
9
7
6
5
4
3
2
1
8
D2 S1 CN5
D4
TP6
TP5
TP7
TP4
TP3
CN6