Cell Transmitter Path - Nokia RH-77 Troubleshooting Manual

2118 (RH-77)
RF Description and Troubleshooting
14. Ensure that the Phone Tx Pout = +25 dBm and the current = 770-860 mA.

Cell Transmitter Path

Table 1 indicates the test points (see
transmitter path. It is recommended that you follow the steps in order. An HP high
frequency probe was used to make the frequency and output power measurements
Test
Part*
Point
T1 Z601 pin1
T2 Z601 pin 3
T3 N803 pin 8
T4 Z803T
T5 C603L
T6 C638T, C654T,
C633R,
C635R,
C603LR
T7 C655R
Page 8
Figure 7: RF PDM dialog box for Tx troubleshooting
Table 1: Cell Transmitter Test Points
Typical
Value/
Function
Frequency
HP85024A
N601-Out -43 dBm/
836.52 MHz
PA-In -25 dBm/
836.52 MHz
PA-Out 5.0 dBm/
836.52 MHz
Iso-Out 2.2 dBm/
836.52 MHz
IF-Out -29 dBm/
228.6 MHz
VR5 2.7 V dc
VR7 2.7 V dc
©2005 Nokia Corporation
Figure 8) to probe when troubleshooting the cell
Typical
Value
Comments
Frequency
Prod Probe
-13.2 dBm/ Output of N601 Driver, Input to
836.52 MHz Tx SAW Filter
-15.4 dBm/ Output of Tx SAW, Input to PA
836.52 MHz
18.3 dBm/ Output of PA, Input to Isolator
836.52 MHz
10.3 dBm/ Output of Isolator, Input to
836.52 MHz Duplexer
-24 dBm/ Tx IF Probing Point at IF Filter
228.6 MHz
VHF VCO/PLL, IQ modulator
supply from UEM
UHF PLL Supply from UEM
Company Confidential
Nokia Customer Care
Issue 01 04/2005