Bang & Olufsen BeoLab 20 User manual

BeoLab 20
Type 6791 – 6797, 6799
Service Manual - version 1.0
English
German, French, Italian, Spanish, Dutch, Japanese, Korean and
Simplified Chinese versions are available in the Retail System
This Service Manual must be returned
with the defective parts/back-up suitcase !
82.0
30.4
39.3

CONTENTS
Survey of modules ................................................................... 1.1
How to service ......................................................................... 1.2
Repair tips ................................................................................ 2.1
Fault flow chart ........................................................................ 2.5
Survey of plugs and pins ........................................................ 2.11
Adjustments - Final check after repair ...................................... 3.1
Replacement of modules .......................................................... 4.1
Specification guidelines for service use ..................................... 5.1
Block diagram .......................................................................... 6.1
Wiring diagram ........................................................................ 6.3
Available parts ......................................................................... 7.1
Change log:
Ver. 1.0 ................................................................. Original release

Survey of modules 1.1
Survey of modules
02.2
48.2
02.1
35.2
35.1
04
30
68
48.3
48.1
47
89
Modules
PCB02.1 Input Panel
PCB02.2 Connector Interface
PCB04 Power Supply
PCB30 Digital Sound Engine
PCB35.1 Amplier
PCB35.2 Amplier
PCB47 LED Indicator
PCB48.1 NTC
PCB48.2 NTC
PCB48.3 NTC
PCB68 Switch Panel
PCB89 Wireless Power Link Rx
Speaker units
Tweeter
Midrange
Woofer

1.2 How to service
How to service
Strategy
This product is to be serviced in the customer’s home.
The repair involves replacement of the module(s). The replaced modules must be
returned for repair at the Bang & Olufsen Module Repair department. Error codes
as well as an adequate fault description must be returned with each replaced part.
For this purpose, use the Exchange Module section in the Retail Order System. To
help the Bang & Olufsen Module Repair department it is very important to answer
the following questions:
1. Which software versions are used in the product?
2. What happens in the actual situation?
3. Error code, the error code contains data that may be used for repairing the
module(s) and must be returned with the defective module(s).
Handling the error code (error log).
a. Make a note of the error code on the Exchange Module section and print it.
b. Use the error code when troubleshooting.
c. Return the error code in the Retail Order System.
d. Before returning the product to the customer, clear the error code.
Preparations before service
Fault explanation and demonstration
Before troubleshooting is initiated, let the customer demonstrate the fault, if
possible.
Recommended tools for service
- Bang & Olufsen ServiceTool
- Static-protective field service
- White gloves
- Shoe covers
- Soft lint-free cloth for cleaning
- WiSpy (Wi-Spy DBx + Chanalyzer Pro)
- Product cover
- Protection stocking to protect the tweeter assembly and decoration ring
Final check after repair
The final check after repair describes the activities that are needed to ensure the
product will be returned in perfect condition to the customer.
Please refer to ‘Final check after repair’ section on page 3.6.

How to service 1.3
Warnings when handling
Static electricity
Static electricity may damage the product.
Static-protective field service kit
A static-protective field service kit must always be used when the product is
disassembled or modules are being handled, since the internal electronics are very
sensitive to static electricity.
Follow the instructions in the Service Manual and use the ESD-mat for both old
and new modules.
When mains voltage on the product is required, remove the connection between
the product and the ESD-mat. This is important to avoid getting injured by mains
voltage.
STATIC ELECTRICITY
MAY DESTROY THE
PRODUCT
ESD
ESD-Mat
Waste of Electrical and Electronic Equipment (WEEE)
Electrical and electronic equipment, parts and batteries marked with this symbol
must not be disposed of with normal household wastage; all electrical and
electronic equipment, parts and batteries must be collected and disposed of
separately.
Management methods for controlling pollution caused by Electronic Information Products
Component
name:
Hazardous substance
Pb Hg Cd Cr(VI) PBB PBDE
Aluminum parts ×ooooo
PCBA ×ooooo
Symbols used in the charts:
o Indicates all homogeneous materials’ hazardous substances content are below the
ST/T 11363–2006 MCV limit.
× Indicates that the hazardous substance content contained in any one of the
homogeneous materials of the part exceeded the MCV limits specified in the
standard SJ/T 11363-2006.

1.4

Repair tips – Fault ow chart 2.1
Repair tips
Check cables .................................................................................... 2.2
Check for newest SW ....................................................................... 2.2
Backup ............................................................................................. 2.2
Restore ............................................................................................. 2.2
Error Log .......................................................................................... 2.2
Autocalibrate .................................................................................... 2.2
LED indicator .................................................................................... 2.2
Description of LED indications ........................................................... 2.2
Product Information - Usage data ..................................................... 2.3
NTC module test ............................................................................... 2.3
Speaker unit test ............................................................................... 2.4
Sound test ........................................................................................ 2.4
Fault ow chart
No function and no LED indication .................................................... 2.5
LED indicator is ashing quickly orange ............................................. 2.7
No sound from speaker in a wired setup ........................................... 2.8
No sound from speaker in a wireless setup ........................................ 2.9
Missing, atttenuated or distorted sound from speaker and no error
indication in error logs .................................................................... 2.10
Survey of plugs and pins ................................................................. 2.11

2.2 Repair tips
Repair tips
Check cables
Always check all external cables as well as internal cables.
Check for newest SW
Always ensure to have the newest software version installed. This is done via the
ServiceTool. Select BeoLab 20 > Software > Automatic Software Update.
The ServiceTool also includes noise and sound sources for testing.
Backup
Before starting the fault nding activity make a complete backup of the product by
means of the ServiceTool (see under Repair > Chassis and follow the instructions).
Restore
After the fault nding activity make a complete restore of the product by means of
the ServiceTool (see under Repair > Chassis and follow the instructions).
Error Log
If an error occurs in the product it is recorded and saved in the error log. The error
log may be helpful in troubleshooting situations. Use the ServiceTool to read out
the error log.
Autocalibrate
Use the ServiceTool > Adjustments > Adjustments > Autocalibrate to check
the amplier output if sound is missing, attenuated or distorted and the error log
doesn’t give a useful explanation. If the autocalibration fails the error can be
located to an error in either the Digital Sound Engine, the amplier modles or the
connection in between. If the autocalibration is successful and sound is still faulty,
it is most likely caused by a speaker driver error or a faulty connection between
amplier modules and speaker drivers.
LED indicator
The LED at the top of the speaker indicates the state of the
product by changing colour (red/orange/green), ashing or
solid. If errors occur during operation, the product will enter an
error state and the LED will start ashing quickly orange.
Description of LED indications
Constant Flashing slowly Flashing quickly
Green Product switches On (10
sec. duration)
Software update is
on-going
Associate mode (only in wireless mode:
ready for pairing)
Orange --The product is failing. The product will
not revert to normal operation. In some
cases it can be resolved by disconnecting/
connecting the mains:
This could be:
- NTC is defective or disconnected.
- Digital Sound Engine is overheating.
- Calibration failed or has not been done
(ashing quickly orange/green).
Red The product is connected
to mains, the product is
switching off or the
product restarts after a
reset.
Not used Not used

Repair tips 2.3
Product Information - Usage data
Usage data is logged in the product which can be very useful information in
troubleshooting situations. Use the ServiceTool to read out the usage data.
Approach (ServiceTool)
Connect a service PC with ServiceTool. Follow the procedure below:
- Connect the ServiceTool to the SERVICE connector on the product as shown:
- Run ServiceTool.
- Be sure that ServiceTool is updated to the latest version. If not, upgrade and restart
ServiceTool.
- Select COM port - ATI COM port
- Scroll down to BeoLab section.
- Select BeoLab 20 and click Launch.
- Click on the PRODUCT tab (if not already shown).
- Click + next to each item to expand the menus.
- Click System Info -> Product ID (the information screen appears).
- Click the Read button and conrm that product data is read out on the screen.
This indicates successful communication between the product and the service PC.
NTC module test
Measure the resistance of the NTC module to determine if
the fault is caused by a defective speaker unit or the NTC
module.
It is recommended to measure on the terminals on the
back of the speaker unit. The NTC module must be
disconnected from the product.
The resistance of the NTC module at 22ºC (72ºF) is approximately 470 kΩ.
If the NTC module is outside the limits, it is defective and must be replaced.
I/O
FREE
WALL
CORNER
L
R
WL
ROLE POS.
RESET
POWER LINK R-INPUT-L IN-TOSLINK-OUT SERVICE

2.4 Repair tips
Speaker unit test
Measure the DC resistance of the speaker unit to determine if the fault is caused
by a defective speaker unit. It is recommended to measure on the terminals on the
speaker unit. The speaker units must be disconnected from the product.
Speaker unit Impedance Nominal resistance Limits
Tweeter 8 Ω 6.7 Ω ± 15%
Midrange 8 Ω 6.2 Ω ± 15%
Woofers *) 2 × 6 Ω 2 × 5.9 Ω ± 15%
*) Each Woofer has two coils.
If the speaker unit is outside the limits, it is defective and must be replaced.
Under normal conditions it is not necessary to replace the gaskets on the speaker
unit, unless they have been damaged by accident.
Sound test
It is possible to test each speaker unit/amplier to check the sound quality, and
determine whether the devices are faulty or healthy. For this purpose use ServiceTool
and refer to the test section.
The Sound Test section features a sound generator which allows the user to send
a pure sound directly to the speaker unit. This feature makes troubleshooting or
testing more easy and targeted.
- Run ServiceTool.
- Be sure that ServiceTool is updated to the latest version. If not, upgrade and restart
ServiceTool.
- Scroll down to BeoLab section.
- Select BeoLab 20 and click Launch.
- Click on the PRODUCT tab (if not already shown).
- Click + next to each item to expand the menus.
- Click Test -> Test Sound (the information screen appears).
- Follow the procedure in Service Tool.