Nokia 3105 Servicehandbuch
RH-48
Troubleshooting - RF
CCS Technical Documentation
Page 26
©
2003 Nokia Corporation Confidential
Issue 1 11/2003
Rx RF
The following Rx RF Troubleshooting table indicates the test points to probe when trou-
bleshooting the Rx RF. It is recommended that you follow the steps in order.
bleshooting the Rx RF. It is recommended that you follow the steps in order.
* The R, L, T, and B values at the end of the part names indicate the Right, Left, Top, and Bottom side
of the part respectively in Figure 17.
of the part respectively in Figure 17.
Rx RF Troubleshooting
Step #
Part*
Function
Typical Value/
Frequency
HP85024A
Typical Value
Frequency
Prod Probe
Comments
R1
L802R (Top
side of the
PWB)
side of the
PWB)
RF-IN
-25dBm/
881.52MHz
881.52MHz
-42dBm
881.52MHz
881.52MHz
Input Connector reference level
R2
L906L
LNA-In
-35dBm/
881.52MHz
881.52MHz
-42dBm
881.52MHz
881.52MHz
Test Duplexer insertion Loss
(Without DC Block)
(Without DC Block)
R3
C903L
LNA-Out
-13/-31dBm
881.52MHz
881.52MHz
-29/-45dBm
881.52MHz
881.52MHz
Test LNA gain ~ 13dB
R4
Z901-R-Bot-
tom, N901-
Pin16
tom, N901-
Pin16
RF Filter
Output
Mixer-In
Output
Mixer-In
-18/-35dBm
881.52MHz
881.52MHz
-30/-45dBm
881.52MHz
881.52MHz
Test RF Filter Insertion loss
(Without DC Block)
(Without DC Block)
R5
C906R
Mixer-
out
out
-5/-21dBm
183.6 MHz
183.6 MHz
-23/-38dBm
183.6MHz
183.6MHz
Test Output on Downconverter on
N901
N901
R6
C912B/R914R
IF Output
to N700
to N700
+1.5/-15dBm
183.6MHz
183.6MHz
-12/-29dBm
183.6MHz
183.6MHz
Test Alfred output to Yoda IF-IC
(N700)
(N700)
R7
R912B/R911L
L.O Input
to N901
to N901
-2.5dBm
1065.12MHz
1065.12MHz
-18dBm
1065.12MHz
1065.12MHz
Test VCO output to Alfred (N901)
Levels are for Channel 384
Levels are for Channel 384
R8
R9056T, L909L,
L901T, R910B
L901T, R910B
VR4
2.7V dc
Power supply to Alfred (N901)
R9
R902B
Rx-SW1
H.G = 2.7V
L.G = 0V
L.G = 0V
LNA gain control, on the Alfred
side, High Gain > 2.5V dc
side, High Gain > 2.5V dc