User Guide

6255/6255i/6256/6256i (RM-19)
RF Description and Troubleshooting Nokia Customer Care
Page 48 ©2005 Nokia Corporation Company Confidential Issue 2 05/2005
Figure 39: N7160 receiver
There are two common explanations for an N7160 failure consisting of high current in
Local Mode with just the Rx turned on:
• No presence of an LO signal
• Input impedance drop is shorting out one of the DC supply pins to the chip
IMPORTANT: You must check for both conditions before replacing the chip. If you
have no LO signal, refer to "UHF Synthesizer" on page 56. If you have a significant supply
voltage drop on one of the supply pins, then replace the N7160.
Table 13: N7160 Conditions and Supply Currents
Condition: Local Mode, Set
Rx Only in RF Main Mode
Supply Current
(From Power Supply)
Good mobile terminal 100mA
No UHF LO signal present 254mA
Pin 13 shorted 255mA
IFAs
LO
Buffer
PCS
RFA
PCS
LNA
Cell
LNA
Cell
RFA