Audio Problems - Ericsson A2618s Troubleshooting Manual

4 Audio Problems

Connect a call from the unit that is to be tested, to a fully functional phone.
Check that the microphone and the earphone of the unit works correctly.
If the unit sounds strange (there is noise, distortion or the sound is "chopped"),
send the unit on according to the local company directives.
Connect a hands-free unit to the system connector of the unit. Check the functionality of the
hands-free.
If it is only the earphone of the unit, that has a low or no sound, go to section 4.1.
If both the hands-free speaker and the earphone of the unit are out of order,
send the unit on according to the local company directives.
If the sensitivity of the microphone is poor, (little or no sound in the reference phone)
go to section 4.2.
If the hands-free microphone does not work, go to section 4.3.
If the hands-free speaker is out of order, go to section 4.4.
If both the speaker and the microphone of the hands-free are out of order, go to section 4.5.
4.1 Earphone out of order
If the earphone is out of order, open the unit and check for liquid damage.
No action is to be taken for a liquid damaged unit, send the unit on according to the local
company directives.
Replace the earphone, according to replacement instructions. Test the unit again.
If the fault remains, replace the elastomer according to replacement instructions.
If the fault still remains, send the unit on according to the local company directives.
4.2 Microphone out of order
If the microphone is out of order, open the unit and check for liquid damage.
No action is to be taken for a liquid damaged unit, send the unit on according to the local
company directives.
Replace the microphone according to replacement instructions. Test the unit again.
Make sure the connector-pads at the board are not mechanically damaged or dirty.
If the fault remains measure the resistance of R501 (0 ohm), R502, R503, (1 kohm) and R500
(22 kohms).
If all the resistances are correct, replace C501 and C502.
If the fault still remains, send the unit on according to the local company directives.
4/00021-2/FEA 209 544/25 A
Trouble Shooting Guide, Standard
10(24)