Nokia 3205 Service Manual 09rm11trouble
CC Technical Documentation
RM-11 Series Transceivers
Troubleshooting - RF (Part 2)
Issue 1 02/2004 Confidential ©2004 Nokia Corporation
RM-11
Troubleshooting - RF (Part 2) CC Technical Documentation
Contents Page
Synthesizer Troubleshooting.......................................................................................... 3
Synthesizer Setup Using Phoenix ................................................................................4
VCTCXO Troubleshooting .........................................................................................4
UHF Synthesizer Troubleshooting ..............................................................................6
UHF Synthesizer Schematic ........................................................................................6
UHF Synthesizer Layout .............................................................................................7
UHF Frequency is Incorrect...................................................................................... 7
RX VHF (Batman LO) Schematic ...............................................................................7
RX VHF Layout ..........................................................................................................8
Incorrect RX VHF Frequency................................................................................... 9
TX VHF Schematic .....................................................................................................9
TX VHF Layout .........................................................................................................10
Incorrect TX VHF Frequency ................................................................................. 10
TX Troubleshooting..................................................................................................... 11
Transmitter Schematic 1 ............................................................................................11
Transmitter Schematic 2 ............................................................................................12
TX Troubleshooting Using Phoenix ..........................................................................13
PCS Band TX Probe Points .......................................................................................15
Cell and AMPS Band TX Probe Points .....................................................................16
TX AMPS Troubleshooting Using Phoenix ..............................................................17
RX Troubleshooting..................................................................................................... 18
Receiver Schematic ...................................................................................................18
Turning on Rx Path Using Phoenix ...........................................................................19
Switching Rx Gain States Using Phoenix .................................................................20
Receiver IF Troubleshooting Layout .........................................................................21
Receiver RF Troubleshooting Layout .......................................................................22
Receiver DC Troubleshooting Layout .......................................................................23
Receiver DC Troubleshooting Layout .......................................................................24
Alfred Receiver Troubleshooting ..............................................................................25
Receiver DC Troubleshooting Alfred ........................................................................26
Control Signals at RF-BB Interface ...........................................................................26
Back Panel Control Signals RF-BB Interface ...........................................................27
Page 2 ©2004 Nokia Corporation Confidential Issue 1 02/2004
RM-11
CC Technical Documentation Troubleshooting - RF (Par t 2)
Synthesizer Troubleshooting
RX VHF Synthesizer
128
128PCS
Phase
Detector
9-Bit B
Counter
Charge
Pump
2 mA
Prescaler
53Cell
53PCS
32/33
5-Bit A
Counter
VCO Band
12Cell
Control
12PCS
RX VHF VCO
Tank
RF_BUS_CLK
RF_BUS_DATA
RF_BUS_EN1X
Reference
Divider
Cell
SYNTH_LE
AFC
UEM
VCTCXO
19.2 MHz
Reference
Divider
Cell
Reference
Divider
Cell
PCS
UHF Synthesi zer
384PCS
640
384
Cell
PCS
Phase
Detector
13-Bit B
Counter
1038 - 1064Cell
1286 - 1323PCS
TX VHF Synthesizer
Phase
Detector
9-Bit B
Counter
360
260
5-Bit A
Counter
0 - 31
Prescaler
5-Bit A
Counter
Cell
PCS
Charge
Pump
4 mA640
Prescaler
32/33
Charge
Pump
2 mA
32/33
20
4
SSB
Mixers
VCO
Band
Control
TX VHF VCO
Tank
UHF VCO
Splitter
UHF LO
RX
FRONT
END
UPP
Figure 1: Synthesizer troubleshooting diagram
Issue 1 02/2004 ©2004 Nokia Corporation Confidential Page 3
RM-11
Troubleshooting - RF (Part 2) CC Technical Documentation
Synthesizer Setup Using Phoenix
Figure 2: Phone Control dialog box
1. Click the LOCAL button on the Phone Control dialog box.
2 Use the following settings for the fields on the RF Main Mode dialog box:
• UHF: Use RX/TX mode in PCS and Cell band. This allows for checking power
to both RX and TX circuits. Typically, use channel 384 in Cell band and 600 in
PCS band.
• RX VHF: Use RX mode; one band is enough.
• TX VHF: Use RX/TX mode in PCS and Cell band.
Figure 3: RF Main Mode dialog box
3. Click the Set button.
Note: Make sure the “RF Main Mode set successfully...” message appears.
VCTCXO Troubleshooting
The VCTCXO frequency is 19.2MHz, which is the reference signal. Without 19.2MHz, the
phone will not power up. This signal goes to Batman, Robin, UHF PLL, and also to the UPP
via a buffer amplifier (D572).
Page 4 ©2004 Nokia Corporation Confidential Issue 1 02/2004
RM-11
CC Technical Documentation Troubleshooting - RF (Par t 2)
Check for the presence of the signal at the following points (use a high-impedance
RF probe):
• CLK19M2_B, clock reference to Batman, should be +4.5dBm
• CLK19M2_R, clock reference to Robin, should be +4.5dBm
• CLK19M2_UPP, clock reference to UPP, should be +7.5dBm
VCTCXO
To Batman PLL
19.2 MHz @ +4.5 dBm
(CLK19M2_B)
To Robin PLL
19.2 MHz @ +4.5 dBm
(CLK19M2_R)
To Baseband UPP
19.2 MHz @ +7.5 dBm
(CLK19M2_UPP)
VR3 = 2.78VDC
VIO = 1.8VDC
Figure 4: Presence of signal test points
If you do not see the VCTCXO signal at any of these points, check the voltages at the
following supply lines:
• VR3, main supply line for VCTCXO circuitry, should be 2.78VDC
• VIO, supply line for buffer amplifier, should be 1.8VDC
Issue 1 02/2004 ©2004 Nokia Corporation Confidential Page 5
RM-11
Troubleshooting - RF (Part 2) CC Technical Documentation
UHF Synthesizer Troubleshooting
Figure 5: UHF Synthesizer dialog box for Cell (left) and PCS (right) bands
UHF LO frequency varies with channel and can be quickly calculated using the
UHF Synthesizer dialog box on the RF menu. Check to see if the LO is actually locked.
Set a channel and check the status of the UHF LO within a very narrow span of 100KHz.
You should see the LO virtually immobile. Nominal UHF LO signal levels are measured
with an RF probe (see the following figures). If you do not see the presence of any LOs,
check DC voltages at the following locations:
• R513, VR1A, supply line for UHF PLL IC. Should be 4.76VDC
• R515, VR4, supply line for VCO IC. Should be 2.76VDC
UHF Synthesizer Schematic
UHF PLL IC
Dual Band VCO
Lock voltage
Loop filter components
Figure 6: UHF synthesizer schematic
Page 6 ©2004 Nokia Corporation Confidential Issue 1 02/2004
RM-11
CC Technical Documentation Troubleshooting - RF (Par t 2)
UHF Synthesizer Layout
VCTCXO reference probing point
UHF PLL IC LMX2310
19.2 MHz @ +4.5 dBm
Lock voltage:
DC between 1V and 3V
RX LO Input to Alfred
Cell channel 384: 1009.62 MHz @ -2.5 dBm
PCS channel 600: 2088.10 MHz @ -12 dBm
Dual-band UHF VCO
Figure 7: UHF synthesizer layout
UHF Frequency is Incorrect
Possible causes:
• Power supplies to PLL IC (N507) are missing or low
• Loop filter components missing or incorrectly installed
• 19.2MHz reference clock missing or low
• Programming is incorrect
• Component failure (VCO or PLL IC)
RX VHF (Batman LO) Schematic
• Operates at a fixed frequency of 256.2MHz. It is the second LO for
down-conversion to I and Q for baseband processing. Refer to the frequency
plan.
TX LO Buffer
RF probe point, TX LO output levels:
Cell channel 384: 1009.62 MHz @ -0.5 dBm
PCS channel 600: 2088.10 MHz @ -20 dBm
• Monitor probing point at C702 for Batman LO. A locked and stable 256.2MHz
with an amplitude of ~= -2.5dBm should be observed on the spectrum analyzer.
• Monitor control voltage at C715. The control voltage at locked state should be
between 1.2 and 1.7VDV for the proper operation of Batman LO.
Issue 1 02/2004 ©2004 Nokia Corporation Confidential Page 7
RM-11
Troubleshooting - RF (Part 2) CC Technical Documentation
Loop filter components
Lock voltage
Resonator
RX VHF Layout
PLL in Batman
Figure 8: RX VHF (Batman LO) Schematic
Lock Voltage Probing Point:
DC voltage between 1V and 2V
RF probing point
256.2 MHz @ -2.5 dBm:
Batman IC with
Integrated PLL
CDMA IF filter
Figure 9: RX VHF layout
Page 8 ©2004 Nokia Corporation Confidential Issue 1 02/2004
RM-11
CC Technical Documentation Troubleshooting - RF (Par t 2)
Incorrect RX VHF Frequency
Possible causes:
• Power supplies to PLL portion of Batman IC (N701) missing or low (VR7)
• Loop filter or resonator components missing or incorrectly installed
• 19.2MHz reference clock missing or low (C512)
• Programming is incorrect
• Component failure (PLL IC)
TX VHF Schematic
There are two fixed LOs — 346.2MHz for Cell band and 416.2MHz for PCS band. This is
the first LO for up-conversion. Refer to the frequency plan.
Monitor the probing point at C638 with a high-impedance RF probe for Robin LO.
A sufficiently strong and stable signal should be observed on the spectrum analyzer.
Monitor control voltage at C632. At this control voltage, the Robin LO is locked (it should
be between 1.2 and 1.8VDC).
Lock voltage
Robin
Loop filter
Resonator
Figure 10: TX VHF Schematic
Issue 1 02/2004 ©2004 Nokia Corporation Confidential Page 9
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