Nokia Mobile Phones NSE-5 Series Service Manual page 239

PAMS
Technical Documentation
Phone doesn't register to the
network
phone doesn't make a call
Analog supply
voltage to COBBA
is > 2.7V?
(C201)
Analog reference to
COBBA is 1.5V?
(C200)
Check:
Supply voltage Vcp (C126) > 4.8V
Supply voltage VRX (C108) > 2.7V
Supply voltage VRX2 (C137) > 2.7V
Supply voltage VSYN_2 (C136) >
2.7V during the receiving slot
Supply voltage VTX (C141) > 2.7V
during the transmitting slot
All OK?
Synthesizer lines:
SEna1 R724
SClk R722
SData R723
Pulses 0–>1 during receiving slot
All OK ?
Issue 1 07/99
or
No
Yes
No
Yes
No
Yes
No
Yes
D
Check N100
Check R200, C140,
C174
Check N100, D300
Check D300
Figure 10.
NSE–5
Troubleshooting
Page 13