Bang & Olufsen BeoLab 3 6881 Service Center Manual - page 15
Service hints and adjustment
Service Hints
Doing fault searching, the BeoLab 3`s LED can give you a hint.
If the LED turns orange in colour it can be a result of a thermal shutdown, remove
the mains and let the speaker cool down. If the LED still light orange when the
mains is connected again, then it is a indication of an internal error.
A internal error indication can be caused by many things, but the most likely is
listed below.
1. The NTC module on the bass driver unit is not connected to the Main chassis, the
plug is disconnected.
2. Tweeter unit is failing (How to measure the driver units is described later on this
page)
3. Bass unit is failing (How to measure the driver units is described later on this page)
4. Error in Switch Mode Power Supply
How to measure the Driver units (treble/bass), using a Ohm-meter :
Dismantle the speaker to get access to the driver unit you want to measure.
Disconnect the unit completely
Measure with an Ohm-meter
The bass unit should be 4,0 Ohm +/- 10% (between 3,6 - 4,4 Ohm)
The treble unit should be 6,4 Ohm +/- 10% (between 5,7 - 6,9 Ohm)
If the measurements are below the – 10% value, it indicates that the driver unit
coil is shortcut.
If the measurements is over the + 10% value, it indicates that the driver unit coil is
disconnected.
Adjustment after driver unit or Main chassis replacement
When a driver or a Main chassis is replaced, the driver unit levels needs to be
adjusted, so the speaker once again is in accordance with specifications.
The adjustment is done with two click-potentiometers, one for treble level
adjustment and one for bass level adjustment. Each potentiometer haves 10 step
(10 * 0,5 dB) and is located on module 03, on the Main chassis.
Service hints and adjustment, English 5.1
Tweeter
Woofer