Bang & Olufsen BeoLab 9 Service Manual download pdf (Page 12)

2.6 Fault ﬂow chart

Fault symptom:

- No function of the PCB7, NTC

Possible cause:

- PCB7, NTC

- Cable W4

- Module 999, Ampliﬁer

Is the loudspeaker in

protection mode?

Visual conﬁrm cable

connection between

Module 999, Ampliﬁer

and PCB7, NTC

Reconnect/replace

cable

Replace PCB7, NTC

Replace Module 999,

Ampliﬁer

To conﬁrm correct operation of the NTC, measure

approx. 9.35V DC at normal room temperature, as

shown in ﬁg 1

(When the temperature is rising, the DC voltage is

going towards 0)

Note:

When the loudspeaker goes into protection mode,

it is nescessarry to disconnect mains and wait one

minute before connecting it again.

Fault symptom:

- No function of S1 and S2

Possible cause:

- Module 999, Ampliﬁer

Is there no function of

switch S1 and/or S2?

Replace Module 999,

Ampliﬁer

Yes

Fig1

Red

Black

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Bang & Olufsen BeoLab 9 Service Manual Page 12