Trouble Shooting Guide, Standard
4/00021-2/FEA 209 544/21 B 5(26)
2 Network Problems
2.1 Find out if the problem is Rx- or Tx-related
Connect the phone (with signalling program) to a GSM test instrument and try to get SERV at
an input signal strength of -68.5dBm.
If the phone does not get SERV, go to section 2.2.
If the phone gets SERV, go to section 2.3.
2.2 The phone does not get SERV
Open the phone and check for liquid damage.
Make sure that the antenna connector (W100, Fig. 2.1) is correctly soldered, and not
mechanically damaged, dirty or oxidised. Clean, resolder or replace if needed.
Fig. 2.1
Check the soldering of N234, N200, Z200 and Z201.
Measure the resistance of R220, R221, R222 and R223, (all 0 ohm).
Replace if incorrect.
Check C312 for bad soldering, resolder carefully if necessary.
Retry to get SERV again with the settings mentioned above.
If the phone gets SERV, go to section 2.3.
If the phone still does not get SERV it is probably within the LO part that the fault lies or the
losses in the signal path are too large. It is also possible that the feed voltages are incorrect.
Open the phone.
Power up the board and start it by pressing the On/Off key.
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