6.8.8 SLR (microphone-path faulty)
Fault code: D 19
Gigaset 4000 Classic/ Comfort
The diaphragm of the microphone is affected by humidity or nicotine with increasing
age or the microphone could be electrically faulty. There will be a higher attenuation
when measuring SLR (sending loudness rating). In most cases the microphone is
Repair by component exchange:
Remove the microphone by desoldering the 2 solder joints.
You can also heat up both pins simultaneously with a broad soldering iron tip and
turn the board upside down, letting the microphone fall out.
Clean pads with desoldering wick and replace it by a new component afterwards.
Attention: Avoid excessive heat (2 seconds maximum)!
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 SLR-test and check
whether the attenuation is o.k..
ICM D CC ST