Bang Olufsen Beomaster 8000 Service Manual 2

Page 1

Bang&0lufsen

Beomaster 8000
TYPE 1901, 1903, 1905,1907

Beolab Terminal
TYPE 1002

SERVICE MANUAL

Page 2

CONTENTS

Circuit Diagrams .......................... . . . ............................. ' .......... . ..... 1
Diagram 1 1-3
Diagram 2 1.4
Diagram 3 1-5
Diagram 4 1-6
Explanation of diagram 1-2
Measuring conditions diagrams 1-8

Function tables (for 9IC-2 and display) ............. 1-7

Survey of display pin connections ... 1-7
Drawing of P09 (Microcomputer) 1-9
BlockDiagrams ................ ......................... ................ 2
Block diagram of power supply ........................................... 2-1
Block diagram of RF circuit 24
Block diagram of AF circuit ......... 2-2
Block diagram of the operating system 2-3
Survey at Semi-conductors ..................... . ......................................... 3
List of transistors 3-1
List of IC's and PEs ,.. 3-2
List of diodes 3-4
List at Electrical Parts .......................... . t . . . . .................................... 4
List of Mechanical Parts .................... . ............................................. 5
Main chassis. Secondary operating panel ............................... 5-2
Primary operating panel ............. 5-4
LF-output and Cooling tower . 5-6
Beolab Terminal ........... . 5-7
Parts not shown 5-7
Cable survey 5-8
Survey of packings for module transport 5-8
Guide to Adjustments .......................... . . . . . ..... 6
No-Ioad current 6-1
Offset output amplifier 6-1
Offset volume control 6-1
Tuning voltage 6-2
Tuner and IF section 6-2
FM-AF output 6-4
AGO ........... 6-4
Signal strength meter 6-4
Opening of stereo decoder ........... . 6-4
Stereo decoder . 6-4
AFT ......... a 6-5
FM signal condi on ..... t 6-5
Resetting of microcomputer ............ 6-6
Display light ........................... 8-6
Remote control receiver 6-6
Dismantling 7
TechnicalData ....... ........................... ................................ a
*lnsulatlon Test 9
Final Testing .................... . ....................... . . .. ............................ 10
Service Tips and Modifications ............... . . . ....... . 11
Method to locate fault in the FM tuning system ,. . 11-1
To be remembered when replacing QICG .......................... . a . 11-2
Re the »Spike Suppressianu circuit on PC4 .. . 11-2
Re P09 (Microcomputer) ............. , 11-2
Table of Input/Output levels .m . 11-3
Diag. 2 includes "Spike Suppressiom circuit on P04 H. 11-5
Diag, 3 includes the previous version of P09 ............................... 11-6

* Read this new section, which in future will from part at new Service manuals.

Page 3

Bang&0|ufsen 1-1

1 FM ........................... diagr. 1 8 Display ....................... dlagr. 3
2 FM Interface .................. diagr. 1 9 Microcomputer ................ dlagr. 3
3 Preamplifier .................. diagr. 2 10 Keyboard Primary ............. dlagr. 3
4 Filter and Tone Controls . . . dlagr. 1-2-3 11 Keyboard Secondary .......... diagr. 3
5 Output Amplifier ............... diagr. 2 12 Terminal Transmitter .......... diagr. 4
6 :zmirtesazzglsgf _____________ diagr. 4 13 Keyboard, Terminal ........... diagr. 4
7 Starting Up Circuit ............. diagr. 4

Beomaster 8000
TYPE 1901, 1903, 1905, 1907

Beolab Terminal
TYPE 1002

Page 36

5-7

Beolab Terminal

Parts Not Shown

Bang&0|ufsen

--t#-12°2"

Viriiififl Modal

150$
1 AD 6 --
5 4. $1
11.07 --i~4l
1505 777777 #4 l
9 wk
12Modul 8002496 PC, remote transmitter 1202 6200036 Set of leads, 8 leads
1201 6200016 Set of leads, 7 leads 1203 7229020 Battery connection
13Moclul 8002492 PC, operation 1301 7500148 Contact spring
14Modul 8052142 Beolab terminal 1407 3010007 Stop
complete 1408 2011023 Screw 212 x 6.5 black
1401 3164379 Cover 1409 2775736 Set of buttons, large, black
1402 2775761 Button »0« 1410 2775737 Set of buttons, small, black
1403 2775760 Set of buttons, large, blue 14 11 3917036 Foam
1404 2775759 Set of buttons, Small, blue 1412 3322058 Window
1405 8700008 Battery 9V 1413 3160031 Cover
1406 3454289 Bottom 1414 3010007 Stop
3532148 Diagram 62702 13 PU lead
339 1564 Outer carton 6270222 Signal lead
3397418 Foam packing, bottom and 3391630 Packing for Beolab Terminal
cover 339000 1 Plastic bag for
6271133 Mains lead with Euro socket Beolab Terminal
6100060 Mains lead for type 1903 7220252 Connector accessories
3917049 Insert

Page 43

Bang&0|ufsen 6 6

Tim.»

D3
Cl

|_|__I
CU
CCI

-r~.
69
a8

3

8 TP11

fiw _
L- *

U
V

/
\ L_l
R11
a Reset of mntrmcumpuler /
Resetting of microcomputer Switch the receiver ON at a random programme.

Connect a DC voltmeter to 8TP11.
Adjust with the potentiometer 8R1] until a reading of 6. 5 V (i 100 mV) is
obtained.
Display light Switch the receiver ON at a random programme.
Comte-ct a DC voitmeter to 8TP14.

Adjust with the potentiometer 8R15 until a reading of 5.0 V is obtained.

Remote control receiver Connect an ocsilloscope to 6TP5.

Activate a random button on the Beolab Terminal. while holding it indirectly or
at some distance from the receiver to avoid overdriving of 61C}.

Adjust with 6L1 until max. signal is obtained.

Page 44

7-1 Bang&0lufsen

DISMANTLING

Replacement of
mains fuses

Removal of release rail

Push-down on the release rail at »Pr0gram« while simultaneously pushing the
rail to the left.

Dismantling of the primary
operating panel

1. Remove the release rail.

2. Remove the screws shown and push the panel inwards. It can now be lifted
into servicing position as shown. '

Page 50

8-2 Bang&0|ufsen

Other data: _
Power supply type 1901 220 volts
type 1903 120 volts
type 1905 240 volts
:ype 1907 110 volts
Power frequency 50-60 Hz __ _>_
Power consumption 10-700 waits
Dimensions W x H x D 67 x 15 x 37 cm 26 3/8" x 6"x 141/2
Weight iv_ 21 kg 46.3 lbs

Subject to change without notice