Nokia NPD-4 Series Technical Documentation Manual page 31

CCS Technical Documentation
Probing
Probing Point location on
board
UHF LO at 1009.62 10E, Figure 5.
MHz for channel Can probe on
384 top of plastic
to check for
presence of LO,
but won't read
accurate
power.
VHF LO at 346.2 11a, Figure 5
MHz for cell band, (you can touch
any channel top of plastic
to verify pres-
ence of LO, but
this won't
measure
amplitude
accurately)
Item to
Setting
check
TX RF AGC See Table 1
TX IF AGC See Table 1
PA AGC See Table 1
PD_CELL High for TX on,
Low for TX off
VREFRF02 fixed
Issue 1 02/2003
Table 2: RF/Analog Probing for Cell/AMPS Transmitter
Probed absolute power (dBm) or
gain/loss (dB), or voltage (v)
Power approximately -3 dBm
Table 3: DC probing for Cell/AMPS transmitter
DC probing
location on DC Voltage
board
12, Figure 8 See Table 1
13, Figure 8 See Table 1
14, Figure 8 See Table 1
49, Figure 5 High=2.6v
Low=0v
50, Figure 5 1.35v
Nokia Corporation
Troubleshooting — RF
Where to start checking if RF
power not correct (soldering,
shorts, DC power applied if
active, correct voltage of DC
signals, otherwise replace)
Check to see if LO is present. If no
LO present, check R515, C511,
C501, C532. Make sure there is
2.7v at TP 10B. If voltage is less
than 2.6v, refer to Baseband regu-
lator troubleshooting. If voltage is
2.7v, check G502 at TP 10A with a
FET probe to see if UHF LO is
present. Check that 19.2MHz clock
is present at TP 10C. If LO is
present but unlocked, check C518,
C508, R508, R503, C509, R550,
and C550. Pay attention to C508,
as it is easily damaged. If LO is
present and locked, but doesn't
appear at TP 10E, check R519,
R509, C506, N502, L501, C514, and
C519.
N601, C612, C613, R607, R605,
C632, R606, C618, R609, C629,
V602, C637, V601, C630, C631,
L611, C638, R604, R601, R602,
R613
Items to check if voltage
incorrect
D400 (UPP), R433, C426, R434,
C427, C429, V420, N601
D400 (UPP), R427, C422, R428,
C423, C430, V421, N601
D400 (UPP), R430, C424, R431,
C425, C431, V422, N601
N601, C649, N603 (pin 4)
D200, C606, N601
Confidential
NPD-4
Page 31