Nokia NPD-4 Series Technical Documentation Manual page 38

NPD-4
Troubleshooting — RF
Table 11: RF probing for Cell CDMA and PCS back end receiver
Probing
Probing point location on
board
Alfred (N750) 46, Figure 6
mixer out= CDMA
RX IF saw (Z753)
in
CDMA RX IF saw 47, Figure 6
(Z753) out= Bat-
man (N701) in
Batman (N701) 40, Figure 6
out= UEM (D200)
in
VHF LO at 256.2 39, Figure 6
MHz
Page 38
Probed absolute
power (dBm) or gain/
loss (dB)
This point not 50
ohms. Will
measure approx -14
dBm for -52 dBm
input and RX AGC
PDM=225.
This point not 50
ohms. Will
measure approx
-47 dBm for -52 dBm
input and RX AGC
PDM=225
Easiest to use RSSI,
see Table 6.
Nokia Corporation
CCS Technical Documentation
Where to start checking if RF
power not correct (soldering,
shorts, DC power applied if
active, correct voltage of DC
signals, otherwise replace)
N750 and supporting components
(Also ensure BAND_SEL low for
Cell CDMA and high for PCS as in
Table 9. Also IF_SEL low for CDMA
as in Table 9), L754, C782, C767,
C761, C786, Z753
Z753, N750 and supporting com-
ponents (including check for proper
voltages on Alfred signaling as in
Table 8), L754, C782, C767, L759,
C770, C771, C772, L760, L761,
N701
N701 (VR5, VR7, VIO, ensure 1.35v
on VREFRF01 as in Table 9, also
check RX_IF_AGC as in Table 9),
R705, C704, R706, C706, C701,
C714, R703, R702, C715, R704,
V701, C716, L701, C702
N701, C701, C714, R703, R702,
C715, R704, V701, C716, L701,
C702, R705, C706
Confidential Issue 1 02/2003