Ericsson R310s Troubleshooting Manual page 12

If the fault remains, open the phone and measure the resistance of R862 (0 ohm), R861 (1.5
kohms), R863 (1 kohm) and R864 (22 kohms). Replace the corresponding component if it is
incorrect.
If all the resistances are correct, replace C863.
If the fault remains, send the unit on according to the local company directives.
4.4 Handsfree microphone does not work
The fault arises when the audio path is interrupted somewhere between the handsfree
microphone (connected through the system connector) and the input of N800. The audio path
is shown in Fig. 4.1.
Open the phone and check for liquid damage, especially around the system connector.
Make sure that the system connector is not damaged.
Make sure that all the components in Fig. 4.1 (R802, R803, R805, R850, R862, R825, C810,
C812, C817, C850 and C862) are mounted on the circuit board.
Measure the resistance of C810 (>60 kohms), C812 (>1 Mohm), C817 (>1 Mohm), R802 (3.9
kohms), R805 (15 kohms), R803 (1 kohm), R862 (0 ohm), R850 (47 kohms) and C850 (>90
kohms). Replace the corresponding component if it is incorrect.
If the fault remains, send the unit on according to the local company directives.
4.5 Handsfree speaker does not work
The fault arises when the audio path is interrupted somewhere between the output of N800
and the handsfree microphone (connected through the system connector). The audio path is
shown in Fig. 4.2.
4/00021-2/FEA 209 544/31 B
Fig. 4.1
Trouble Shooting Guide, Standard
12(23)