CCS Technical Documentation
Troubleshooting
RH-10
Issue 1 09/2002
Nokia Corporation Confidential
Page 27
Table 7: DC Probing for Receiver
Table 6: RF Probing for AMPS 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 =
AMPS RX IF
saw (Z752) in
36, Figure 2
This point not 50 ohms. Will meas-
ure approx. -28 dBm for -52 dBm
input and RX AGC PDM = 225
N750. IF_SEL low for CDMA and
high for AMPS. R722, C750, L771,
R723, C756, L770, L757, C758,
L755, C769, C766, C784, L764,
C781, Z752
AMPS RX IF
filter (Z752)
out = Batman
(N701) in
37, Figure 2
This point not 50 ohms. Will meas-
ure approx -46 dBm for -52 dBm
input and RX AGC PDM = 225
Z752, L765, C777, L766, C778,
L768, L767, C779, N701 (VR5, VR7,
VIO)
Batman (N701)
out = UEM
(D200) in
38, Figure 3
RSSI most useful
N701 (VR5, VR7, VIO, ensure 1.35v
on VREFRF01; also check
RX_IF_AGC), R706, C704, R705,
R704, V701, C716, L701, C702,
C715, R702, C714, R703, C701
VHF LO at
256.2 MHz
39, Figure 2
N701, C701, C714, R703, R702,
C715, R704, V701, C716, L701,
C702, R705, C706
Item to check
Setting
DC probing
location on board DC voltage
Items to check if voltage
incorrect
RX IF AGC
See PDM set-
tings
40, Figure 3
See typical volt-
ages
D400, R436, C428, C435, N701
GAIN_CTL
High = LNA
high gain
Low = LNA low
gain
55, Figure 2
High = 2.4v min
Low = 0.3v max
N701, N750, R721, C753
IF_SEL
High = AMPS
Low = CDMA
57, Figure 2
1.35v
D200, C706, N701