Ericsson R310s Troubleshooting Manual page 6

Trouble Shooting Guide, Standard
Measure the voltage on pin 5 of N234 (3.8V).
If the voltage is incorrect, measure the resistance of L211 (0 ohms).
If the resistance is incorrect, replace L211.
If the resistance of L211 is correct, measure the resistance from L211 to ground (>1 Mohms).
If it is incorrect, replace C214, C211 and C212.
Measure the voltage on pin 47 of N234 (3.8V).
If the voltage is incorrect, measure the resistance of R345 (18 ohms).
If the resistance is incorrect, replace R345.
If the resistance of R345 is correct, measure the resistance from pin 47 of N234 to ground
(>0.5 Mohm).
If the resistance is low, replace C345.
Measure the voltage on pin 62 of N234 (3.8V).
If the voltage is incorrect, measure the resistance of L370 (0 ohms).
If the resistance is incorrect, replace L370.
If the resistance of L370 is correct, measure the resistance from L370 to ground (>0.5
Mohm).
If the resistance is low, replace C373 and R362.
The VVCO voltage for D300:
Measure the voltage on R303 (3.8 V).
If the voltage is incorrect, measure the resistance of R303 (18 ohms).
If the resistance is incorrect, replace R303.
If the resistance of R303 is correct, measure the resistance from R303 to ground (130 kohms).
If the resistance is low, replace C303.
If the fault remains, send the unit on according to the local company directives.
2.3 Connect a call at –68.5dBm input signal and power
level 5
If you are able to connect a call, go to section 2.4.
If you are not able to connect a call, 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 or replace it if needed. Also check that the antenna connector surface on the
board is clean and not oxidised.
Check the soldering on N551, N400 and the components around them.
Try to connect a call again.
If you still are not able to connect a call, send the unit on according to the local company
directives.
4/00021-2/FEA 209 544/31 B 6(23)