User Guide

NPE-3
Baseband Trouble shooting PAMS Technical Documentation
3DJH 1RNLD0RELOH3KRQHV/WG ,VVXH
Phone doesn’t register to the network
or
phone doesn’t make a call
C254 (VCOBBA) > 2.7V
C240 (Vref) = 1.5V
Check supply voltage, during RX slot:
C157 (VCP) > 4.8V
C137 (VRX) > 2.7V
C131 (VSYN_1) > 2.7V
C133 (VSYN_2) > 2.7V
- during TX slot:
C142 (VTX) > 2.7V
Check synthesizer lines, during RX slot:
J501/J505 (SLE)
J502/J506 (SCLK)
J503/J507 (SData)
= Pulses "0" -> "1"
Check RF control lines, during RX slot:
R708 (RxC, N240) = 0 - 2.3V max.
R604 (AFC, VCXO) = 0 - 1.2V typ.
Check analog data signals, during RX slot:
R510 (RxIN, Cobba) = 0 - 1.5V DC
C519 (RxIP, Cobba) = 0 - 1.5V DC
Received signal is biased to DC,
nominal amplitude = 50mVpp, freq. = 13MHz
Check RF control lines, during TX slot:
R518 (TxC, Cobba) = 0 - 2.3V max.
R512 (TxP, MAD2) = "0" - "1" (2.8V)
Check analog data signals, during TX slot:
(TxIN, Cobba)
(TxIP, Cobba)
(TxQN, Cobba)
(TxQP, Cobba)
Transmitted signal is biased to DC,
nominal amplitude = 300mVpp, freq. = 64KHz
Check N102 CCONT
Check C144, C240, R240
Check N102 CCONT
and D301 MAD2
Check D301 MAD2
Check N240 Cobba
If DC failure:
Check N240 Cobba
Else:
Check RF part
If TxC failure:
Check N240 Cobba
If TxP failure:
Check D301 MAD2
Check N240 Cobba
Check RF part
Yes
No
No
Yes
No
Yes
No
No
Yes
Yes
No
Yes
Yes
No
No
Yes
Phone doesn’t register to the network...