Siemens AC265 - Repair of Receiver

Siemens Home and Office
Communication Devices GmbH & Co. KG
Confidential 12 SHC CC RCT
Version 1.5 J. Junggebauer
5.2 Repair of receiver
Affected unit: Handset
Diagnosis code IRIS:
72100 (ACOUSTICS / RECEIVING / EARCAP)
Repair level: Level 1
Components: Receiver
Needed equipment: Multimeter
Working material:
None
Diagnosis:
The diaphragm of the earphone could be affected by deposits with increasing age.
There will be a higher attenuation when measuring RLR (receiving loudness rating). In most cases
the earphone capsule is defective.
If there is no noise audible on the earphone when making a sidetone check it’s also possible that the
wire of the coil is broken.
Check the resistance of the coil with a multimeter.
The typical resistance is appr. 120 ohm +/- 20%. In other cases replace it.
Repair:
Replace receiver.
Test:
Put the repaired board in a testhousing.
Make a sidetone check by blowing into the microphone and checking the volume
of the noise on the earphone.
If there is a telephone tester with acoustic testhead make a RLR-test and check whether the
attenuation is o.k..