RH-10
Troubleshooting
CCS Technical Documentation
Page 28
Nokia Corporation Confidential
Issue 1 09/2002
Table 8: RF Probing for Cell CDMA Back-end Receiver
Probing point
Probing
location on
the board
Probed Absolute Power (dBm) or
gain/loss (dB)
What to check if RF power not
correct (soldering, shorts, DC
power applied if active, correct
voltage of DC signals, otherwise
replace)
Alfred (N750)
mixer out =
CDMA RX IF
saw (Z753) in
46, Figure 2
This point not 50 ohms. Will meas-
ure approx. -14 dBm for -52 dBm
input and RX AGC PDM = 225
N750 and supporting components
(ensure BAND_SEL low for Cell
CDMA and high for PCS as in
Table 3d. Also, IF_SEL low for
CDMA), L754, C782, C767, C761,
C786, Z753
CDMA RX IF
saw (Z753) out
= Batman
(N701) in
47, Figure 2
This point not 50 ohms. Will meas-
ure approx. -47 dBm for -52 dBm
input and RX AGC PDM = 225
Z753, N750 and supporting com-
ponents (including check for proper
voltages on Alfred signaling), L754,
C782, C767, L759, C770, C771,
C772, L760, L761, N701
Batman (N701)
out = UEM
(D200) in
38, Figure 3
Easiest to use RSSI
N701 (VR5, VR7, VIO, ensure 1.35v
on VREFRF01), R705, C704, R706,
C706, C701, C714, R703, R702,
C715, R704, V701, C716, L701,
C702
VHF LO at
256.2 MHz
39, Figure 2
N701, C701, C714, R703, R702,
C715, R704, V701, C716, L701,
C702, R705, C706
Table 9: RF DC Power Supplies
Supply
Voltage
Supplied Components
VR1A
4.75
VCTCXO, UHF PLL
VR1B
4.75
Robin
VR2
2.78
Robin, Power Detector
VR3
2.78
Robin, VCTCXO
VR4
2.78
UHF PLL
VR5
2.78
Batman
VR6
2.78
Robin, UHF PLL
VR7
2.78
Batman
VIO
1.8
Robin, UHF PLL
VRX
1.8
Alfred
VPLL
2.78
UHF PLL
VBAT
3.1-4.2
PA