The Phone Doesn't Register To The Network - Nokia NSC/W–1/3 Series Disassembly & Troubleshooting Instructions

PAMS
Technical Documentation
The phone doesn't register to the network or phone doesn't make a call
Phone doesn't register to the network
Analog supply voltage VCOBBA is >2.7 V
at pin 7,12 ... of Cobba (N250)
Analog reference voltage Vref is 1.5 V
RX AMPS: VR1, VR2, VR4/VR8, VR6, V5V
RX DAMPS: VR1, VR2, VR4/8, VR6, V5V
RX TDMA: VR1, VR6, V5V, VR9, VR10, VR12
TX AMPS: VR3, VR5, VR7, TXPWR3
TX DAMPS: VR3, VR5, VR7, VR7_bias, TXPWR3
TX TDMA: VR11
Note; Each VR is to be checked only once!
Synthesizer lines: SEna2 (N880 pin 13 ),
pulses 0 –> 1 during off burst
AGC1 (N250 pin 14) 0 ––>2.3 V max during receiving burst
AFC (N250 pin 13) 0 – 1.2 V typ. during receiving burst
Analog data signal IF2AN (N250 pin 8) –> 0.6 Vpp, 0–>2.2 V DC
Analog data signal IF2AP (N250 pin 7) –> 0.6 Vpp, 0–>2.2 V DC
Digital data signal IF2DN (N250 pin 10) –>170 mVpp typ,
Digital data signal IF2DP (N250 pin9) –>170 mVpp typ, 0–>2.7 V DC
DAX signal (N250 pin 62) pulses 1 –> 0 during receiving slot
TX control lines: TxC (N750 pin 11) 0 –> 2.3 Vmax during transmit burst
TXA (N750 pin 2) goes 0–>1 (2.8 V) during modulation
TXLX1 (D202 pin 96) and TXLX2 (D202 pin 98) 0–> 1 (2.8 V)
TXLX are low during PL7 to PL2 and high during PL10 to PL 8
Analog data signals: TxIN (N250 pin 21) 0–> 0.8 V DC during transmit slot
TxQN (N250 pin 19) 0 –>0.8 V DC during transmit slot
Used IQ signals are biased to 0.8V DC and AC amplitude is 400 mVpp
Original 11/99
Disassembly & Troubleshooting Instructions
or
phone doesn't make a call
YES
YES
at pin 9 of Cobba (N250)
YES
YES
SClk (N880 pin 11)
SData (N880 pin 12)
YES
YES
Frequency is 450 MHz
YES
YES
YES
TxIP (N250 pin 20) 0 –>0.8 V DC during transmit slot
TxQP (N250 pin 18) 0 –>0.8 V DC during transmit slot
max, frequency is 12 kHz max
Check
NO
N250
Check
NO
R256
MAD D202
NO
CCONT N150
PENTA N702
NO
MAD
D202
NO
COBBA
N250
NO
N250 if DC is failed
0–> 2.7 V DC
RF part if benefit signal is failed
NO
Check
N250
N250 if TxC is failed
NO
D202 if TXA is failed
NO
Check
N250
Check
YES
RF part
NSC/W–1/3
Check
Check
Check
Check
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