Ericsson R310s Troubleshooting Manual page 7

Trouble Shooting Guide, Standard
2.4 Read the RX-level while call is connected
Make sure that the output power is 31-35 dBm for GSM power level 5 and that the RX-level
value is 43±3 steps.
Lower the input signal to –102dBm and make sure that the RX-level value is 6-12 steps and
that the RX-quality value is 0-2 steps.
If the values are within the limits, but you are not able to connect a call on the "real" net,
make sure that the phone has not been locked out of the system due to theft.
If the RX-level value is too high the phone needs to be calibrated, send the unit on according
to the local company directives.
If the RX-level value is less than 38 steps at an input signal of –68.5dBm or less than 5 steps
at an input signal of –102dBm then the fault is RX-related.
Open the phone and check for liquid damage.
Make sure that the antenna connector in the frame is not mechanically damaged, dirty or
oxidised. Clean the connector or replace it if it is needed. Also check that the antenna
connector surface on the board is clean and not oxidised.
Check the soldering on N200, Z200, Z201 and N201.
Remove L204 and measure the resistance from pin 2 of Z200 to ground (>100 kohms). The
resistance is usually only a few ohms when Z200 is faulty.
If the resistance is incorrect, replace Z200 and mount L204.
If the fault remains the unit may have to be calibrated, send the unit on according to the local
company directives.
4/00021-2/FEA 209 544/31 B 7(23)