Nokia RH-10 Series Troubleshooting Manual page 26

RH-10
Troubleshooting
AMPS ch 384 HighGain
CELL ch 384 LowGain
CELL ch 384 HighGain
7 RSSI should be within +/- 2 dB of actual RX signal above -104 dBm and +2/-4dB
below -104 dBm
8 In AMPS, ensure 230 mV on I,Q traces of Batman out, probing point 38 of
Figure 3.
9 Use CW signal for AMPS, use CDMA signal for CELL. Call box can generate both
Table 5: RF Probing for Cell CDMA and AMPS Front-end Receiver
Probing
Probing point location on
the board
Cell duplexer 32, Figure 1
(Z803) out =
Alfred (N750) in
Alfred (N750) LNA 33, Figure 2
out = cell RX saw
(Z751) in
Cell RX saw (Z751) 34, Figure 2
out = Alfred
(N750) mixer in
UHF LO at 10, Figure 1
1009.62 MHz in Can probe on
Cell CDMA/AMPS top of plastic
for channel 384 to check for
presence of LO,
but won't read
accurate
power
Page 26
Table 4: Receiver Probing (PDM and voltage)
PDM PDM
lower limit upper limit
127 215
-1 106
-119 -3
Probed Absolute Power (dBm) or
gain/loss (dB)
Loss = 2-4 dB through duplexer
Gain = 12-14 dB for high gain
mode (GAIN_CTL=high. Use RF
AGC status window to monitor
state)
Loss = -3 to -5dB for low gain
Loss = -1-3 dB through SAW filter
Approx -3 dBm
Nokia Corporation
CCS Technical Documentation
Voltage for
PDM mean
PDM mean
173 1.19
60 0.99
-64 0.78
What to check if RF power not
correct (soldering, shorts, DC
power applied if active, correct
voltage of DC signals, otherwise
replace)
Z803, L750, N750 (VRX)
N750. Also, IF_SEL low for CDMA
and high for AMPS. Ensure
GAIN_CTL high if RX power is
below the LNA switch point. Z751,
C755, L752, C757, R721, C753,
R723, C756
Z751, N750, R722, C750, R723,
C756, L757, C758
If LO is present but off freq (could
be off by hundreds of MHz), then
VCO G502 is at least putting out a
signal. If LO not present, check
G502, L509, R505, R515 first. Else,
check C511, C501, C532, C550,
R550, C509, R503, C508, R508,
C518, N501, R506, C516, C515,
C521, R513, C504. Lastly, check
R523, R519, R509
Confidential
RX power in
-65 dBm
-65 dBm
-95 dBm
Issue 1 09/2002