User Guide

PAMS
Technical Documentation
NSE–8/9
Troubleshooting
Page 15
Issue 1 07/99
Phone doesn’t register to
the network or
phone doesn’t make a call
Analog supply
voltage to
COBBA is > 2.7V
(C218) and stable
?
Check N100
Analog reference
to COBBA is 1.5V
(C205) and stable
?
No
Yes
Check R207, C205, C123
and C124.
Check Vref and load on it
Check:
Supply voltage Vcp (C132) > 4.8V
Supply voltage VRX_1 (C101) > 2.7V
Supply voltage VRX_2 (C104) > 2.7V
Supply voltage VSYN_2 (C103) > 2.7V
during the receiving slot
Supply voltage VTX (C125) > 2.7V
during the transmitting slot
No
Yes
All OK?
Check N100, D300 and load in
RFon defective lines
D
No
Yes
Synthesizer lines:
SEna1 R724
SClk R722
SData R722
Pulses 0–>1 during receiving slot
All OK ?
Yes
Check D300
No
Figure 4–11