6.8.9 RLR (earphone-path faulty)
Fault code: D 20
Gigaset 4000 Classic/ Comfort
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 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 cut off.
Check the resistance of the coil with a multimeter.
If you measure a nearly infinitely high resistance, the wire may be cut off.
Repair by component exchange:
Use new earphone capsule.
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..
ICM D CC ST