CCS Technical Documentation
Troubleshooting — RF
NPD-1
Issue 1 11/2002
Nokia Corporation Confidential
Page 33
PCS PA (N802) out
= PCS isolator
(Z801) in
21, Figure 5.
Probing here
not recom-
men-ded
unless neces-
sary. Best to
measure on RF
connector.
See Table 1. Best to measure on RF
connector.
N802 (3.6v on Vbat), Z801, R802,
L801, L802, D400, N601 (since Iref,
also check PA_AGC as in Table 5)
PCS isolator
(Z801) out= PCS
duplexer (Z804) in
22, Figure 5
Loss=0.6 dB through isolator
Z801, Z804
PCS duplexer
(Z804) out =
diplexer (Z805) in.
In singlemode
phones, a resistor
replaces the
unused duplexer:
R810 for PCS only,
R811 for Cell only.)
23, Figure 7
Loss=3 dB through PCS duplexer,
TX to ANT port
Z801, N802 (Vbat), R802, Z804,
Z801, Z805, L750, N750, X811
X814
Diplexer (Z805)
out= RF connector
(X814) in.
9, Figure 7
Loss=0.5 dB through diplexer
Z803, Z804, L750, N750, C801,
L812, X814. If no cable connected
to X814, then additionally: X811
UHF LO at
2088.1 MHz for
PCS on channel
600
10E, Figure 5.
Can probe on
top of plastic
to check for
presence of LO,
but won’t read
accurate
power
Approx –3 dBm
Check to see if LO is present. If no
LO is present, check R515, C511,
C501, C532. Make sure there is
2.7V at TP 10B. If voltage is less
than 2.6V, then refer to baseband
regulator troubleshooting. If volt-
age is 2.7V, check G502 at TP 10A
with a FET probe. Check that the
19.2 MHz clock is present at TP
10C. If LO is present but unlocked,
check C518, C508, R508, R503,
C509, R550, and C550. Pay partic-
ular attention to C508, as it is eas-
ily damaged. If LO is present and
locked, but doesn’t appear at TP
10E, then check R519, R509, C506,
N502, L501, C514, and C519.
VHF LO at
416.2 MHz for
PCS, any channel
11a, Figure 5
N601, C612, C613, R607, R605,
C632, R606, C618, R609, C629,
V602, C637, V601, C630, C631,
L611, C638, R604, R601, R602
Table 4: RF/Analog Probing for PCS transmitter
Probing point
Probing
location on
board
Measured power (dBm) using RF
probe, 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)