Radio Frequency; Gsm Calibration During Production; Gsm Afc Calibration; Gsm Rx Path Loss Calibration - Lenovo S960 Service Manual

LENOVO S960 Cellphone Service Manual

4 Radio frequency

4.1 GSM calibration during production


Problem: AFC calibration failed.

Reason: Connections of RF test cable are not reliable during the calibration. TCXO is fitted
reversely or has a dry joint problem. Receiving channel is open.

Troubleshooting:
Check whether the crystal (X2101) is fitted reversely or
has a dry joint problem.
Is the separate calibration of GSM
Rx Path Loss successful?
Replace main chip MT6167(U2105) or
MT6589(U1101).

Note: Normally you need to re-calibrate the corresponding components after the replacement.

Problem: Rx Path Loss calibration failed.

Reason: During the calibration, connections of RF test cable are not reliable; components in
receiving channel (such as RF connectors), PA module, saw filter and peripheral capacitors have

4.1.1 GSM AFC calibration

AFC calibration
failed.
Check whether
connections of RF cable
and fittings are reliable.
Y
N
N

4.1.2 GSM Rx Path Loss calibration

N
Re-connect and
calibrate.
Y
Y
Analyse the Rx Path Loss
problem at first.
Page 24
Re-solder.