Nokia RH-77 Operating instructions

Nokia Customer Care
2118 (RH-77)
Mobile Terminal
Issue 01 04/2005 Company Confidential ©2005 Nokia Corporation
RF Description and
Troubleshooting

2118 (RH-77)
RF Description and Troubleshooting Nokia Customer Care
Page 2 ©2005 Nokia Corporation Company Confidential Issue 01 04/2005
Contents Page
Components ..................................................................................................................................................... 3
Transmitter Troubleshooting ....................................................................................................................... 5
Low Tx Power ................................................................................................................................................5
Cell Transmitter Setup ...............................................................................................................................5
Cell Transmitter Path ..................................................................................................................................8
Tx AGC Tuning ........................................................................................................................................ 11
Cell Power Amplifier ............................................................................................................................. 12
Cell PMIC.................................................................................................................................................. 12
Cell IF/RF AGC and PA Control........................................................................................................... 14
Cell Power Detector .............................................................................................................................. 16
Tx System Block Diagram ........................................................................................................................18
Receiver Troubleshooting .......................................................................................................................... 19
Rx IF ...............................................................................................................................................................19
Switching the Gain ...................................................................................................................................24
Rx RF .............................................................................................................................................................26
Rx AGC (Cell mode)............................................................................................................................... 28
Receiver Block Diagram ...........................................................................................................................30
Synthesizer Troubleshooting .................................................................................................................... 31
Synthesizer Setup ......................................................................................................................................31
VCTCXO Tuning ...........................................................................................................................................33
VCTCXO Reference Clock ..................................................................................................................... 36
Synthesizer Block Diagram .....................................................................................................................37
UHF Synthesizer .........................................................................................................................................38
Rx VHF ..........................................................................................................................................................39
Tx VHF ...........................................................................................................................................................40

Nokia Customer Care RF Description and Troubleshooting
2118 (RH-77)
Issue 01 04/2005 ©2005 Nokia Corporation Company Confidential Page 3
Components
Figure 1 and Figure 2 illustrate the main components of the 2118.
Figure 1: RF components (top)
RF connector LCD module connector

2118 (RH-77)
RF Description and Troubleshooting Nokia Customer Care
Page 4 ©2005 Nokia Corporation Company Confidential Issue 01 04/2005
Figure 2: RF components (bottom)
Rx IF CDMA filter
Rx downconverter
Cell Tx PA
Cell isolator
Rx IC LNA+downconverter
Cell Rx RF SAW filter
Cell Tx SAW filter
Tx Up-Converter
VCO
VCTCXO
UPP
UEM
PA PMIC DC-DC converter
On/Off switch
Flash
Pop-port connector
Cell duplexer
Battery converter
SIM card connector

Nokia Customer Care RF Description and Troubleshooting
2118 (RH-77)
Issue 01 04/2005 ©2005 Nokia Corporation Company Confidential Page 5
Transmitter Troubleshooting
Low Tx Power
Use Phoenix to turn on the transmitter in Local Mode, and check the following:
• Verify the current (0.7 - 1A for max power, mode, and channel dependent).
• Use a microscope to visually inspect the PWB for proper placement, rotation, and
soldering of components.
• Look for the presence of a Tx signal on the spectrum analyzer at the correct
frequency:
• If the signal is not on frequency, check in the 100 MHz span.
• If the signal is present but off frequency, check the synthesizer. Most likely,
one of the synthesizers is not locked, or the VCO has no output signal.
• If the signal is not present, or is present but low in amplitude, use the
probing tables to determine where in the chain the fault occurs.
• Verify that the AGC PDMs are set for the desired Tx power as listed in the Tx AGC
Tuning table on page 11, and ensure that the AGC voltages are correct.
• Check the synthesizers for proper frequency and amplitude.
• Ensure that the power supplies to the transmitter have the correct voltage.
Cell Transmitter Setup
Use the following steps to set up the mobile terminal for Tx troubleshooting in Phoenix.
1. Open the Phone Control dialog box.
Figure 3: Phone Control dialog box for Tx troubleshooting

2118 (RH-77)
RF Description and Troubleshooting Nokia Customer Care
Page 6 ©2005 Nokia Corporation Company Confidential Issue 01 04/2005
2. Click the LOCAL button in the Phone State area to put the mobile terminal into
Local Mode.
3. Select the following values on the RF Main Mode dialog box:
•Band = Cell (CDMA)
•Channel = 384
•Mode = Rx/Tx
Figure 4: RF Main Mode dialog box for Tx troubleshooting
4. Click Set.
Note: Be sure that the “RF Main Mode set successfully” message appears in the
status bar.
5. Select the Rho ON check box on the CDMA Control dialog box.
Figure 5: CDMA Control dialog box for Tx troubleshooting
6. Click Execute.
7. At this point you should be able to measure Tx Pout at the RF connector. The cell
band Tx Pout =0 to 2 dBm. If you do not see these values, set the AGC PDM for
25 dBm and probe the Tx path to figure out where in the path the fault occurs.
8. Open the General I/O dialog box to set the PA gain state.

Nokia Customer Care RF Description and Troubleshooting
2118 (RH-77)
Issue 01 04/2005 ©2005 Nokia Corporation Company Confidential Page 7
9. Enter 10, 13, 12, and 8 in the PIN # fields.
Figure 6: General I/O dialog box for Tx troubleshooting
10. Select the boxes in the Enable column for each pin.
11. Click the Get All button.
12. Ensure that all of the pins have a value of H in the State column. (Click the L
values to change them to H values.)
13. Adjust the following PDM field values on the RF PDM dialog box:
•Tx IF AGC = -280
•Tx RF AGC = -280

2118 (RH-77)
RF Description and Troubleshooting Nokia Customer Care
Page 8 ©2005 Nokia Corporation Company Confidential Issue 01 04/2005
Figure 7: RF PDM dialog box for Tx 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 Figure 8) to probe when troubleshooting the cell
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
Table 1: Cell Transmitter Test Points
Test
Point Part* Function
Typical
Value/
Frequency
HP85024A
Typical
Value
Frequency
Prod Probe
Comments
T1 Z601 pin1 N601-Out -43 dBm/
836.52 MHz
-13.2 dBm/
836.52 MHz
Output of N601 Driver, Input to
Tx SAW Filter
T2 Z601 pin 3 PA-In -25 dBm/
836.52 MHz
-15.4 dBm/
836.52 MHz
Output of Tx SAW, Input to PA
T3 N803 pin 8 PA-Out 5.0 dBm/
836.52 MHz
18.3 dBm/
836.52 MHz
Output of PA, Input to Isolator
T4 Z803T Iso-Out 2.2 dBm/
836.52 MHz
10.3 dBm/
836.52 MHz
Output of Isolator, Input to
Duplexer
T5 C603L IF-Out -29 dBm/
228.6 MHz
-24 dBm/
228.6 MHz
Tx IF Probing Point at IF Filter
T6 C638T, C654T,
C633R,
C635R,
C603LR
VR5 2.7 V dc VHF VCO/PLL, IQ modulator
supply from UEM
T7 C655R VR7 2.7 V dc UHF PLL Supply from UEM

Nokia Customer Care RF Description and Troubleshooting
2118 (RH-77)
Issue 01 04/2005 ©2005 Nokia Corporation Company Confidential Page 9
* 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 8 and Figure 9.
T8 C636L, C624T,
L609B, C612L,
C630B, L607B
VR2 2.7 V dc Mixer, driver, and IF supply from
UEM
T9 C605R, C606R VAGC-Tx 0.2 to 1.8 V dc Tx AGC Control Voltage from
UPP.
0.2 V = Max Gain
1.8 V = Min Gain
T10 C658R, C600T VIO-Tx 1.8 V dc Supply for Digital circuits from
UEM
T11 C805B, C810T,
C816R
VBAT 3.6 V dc Battery Voltage
(Nominal Voltage 3.6 V dc)
T12 C802L, C813L VPA 3.6 V dc
(High Gain)
Main PA Supply Voltage from
PMIC. Lgain=0.8 V,
Mgain=-1.25 V, Hgain=Vbat
T13 C814R VG 1.8 V dc
(Enable)
PA Gate Voltage (Enable/Disable)
Disable=0 V
Table 1: Cell Transmitter Test Points (Continued)
Test
Point Part* Function
Typical
Value/
Frequency
HP85024A
Typical
Value
Frequency
Prod Probe
Comments

2118 (RH-77)
RF Description and Troubleshooting Nokia Customer Care
Page 10 ©2005 Nokia Corporation Company Confidential Issue 01 04/2005
Figure 8 shows each test point for the N601 TXIC section from Table 1, “Cell Transmitter
Test Points,” on page 8. Always attach a 20 dB pad (11881-60001) when probing with an
HP85024A high-frequency probe.
Figure 8: (Top) PWB. (Bottom left) A zoomed view of the testing points on the N601 TXIC section.
(Bottom right) A zoomed view of the N601 TXIC section with part numbers.