Nokia 6670, 7610 Service Manual 06b rh51 rf trouble

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Nokia Customer Care

RH-51/52, RH-67/68 Series Cellular Phones

6(b) - RF Troubleshooting and

Manual Tuning Guide

Company Confidential

RH-51/52, RH-67/68 Company Confidential 6(b) - RF Troubleshooting Nokia Customer Care

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Company Confidential RH-51/52, RH-67/68

Nokia Customer Care 6(b) - RF Troubleshooting

Table of contents

Page No

Introduction ...............................................................................................................................................7

General troubleshooting ..................................................................................................................... 7

RF key component placement...............................................................................................................9

Receiver troubleshooting......................................................................................................................10

General description ............................................................................................................................10

General instructions for RX troubleshooting ..............................................................................12

Measuring RX I/Q signals using RSSI..........................................................................................12

Measuring RX performance using SNR measurement ...........................................................14

Measuring the RX module manually using oscilloscope and spectrum analyzer...........15

GSM 900/850.....................................................................................................................................15

GSM1800 ............................................................................................................................................17

GSM1900 ............................................................................................................................................19

Measurement points in the receiver ...........................................................................................21

Tuning RX using Phoenix......................................................................................................................23

RX channel select filter calibration ...............................................................................................23

RX calibration ....................................................................................................................................23

RX band filter response compensation.......................................................................................25

Transmitter troubleshooting................................................................................................................27

General description ............................................................................................................................27

Preparation for troubleshooting .....................................................................................................28

Fault-finding chart: TX-BB interface and control signals.....................................................30

Fault-finding chart: RF side of transmitter...............................................................................31

Transmitter tuning..................................................................................................................................34

TX IQ tuning .........................................................................................................................................34

TX power level tuning ........................................................................................................................39

Synthesizer troubleshooting................................................................................................................43

General description ............................................................................................................................43

Assumption ...........................................................................................................................................45

Preparation for troubleshooting .....................................................................................................46

Measuring the synthesizer manually using spectrum analyzer ............................................47

Troubelshooting chart for synthesizer ..........................................................................................47

Bluetooth troubleshooting...................................................................................................................49

Bluetooth component placement ..................................................................................................49

Bluetooth settings for Phoenix ................................................................................................

Bluetooth troubleshooting diagram ..............................................................................................52

.......49

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Nokia Customer Care 6(b) - RF Troubleshooting

List of figures

Page No

Fig 1 RF key components.........................................................................................................................9

Fig 2 RF key components.........................................................................................................................9

Fig 3 Receiver signal path .................................................................................................................... 10

Fig 4 Troubleshooting chart for EGSM900 (GSM850).................................................................. 16

Fig 5 Probed RX I/Q signals J827, 828.............................................................................................. 17

Fig 6 Troubleshooting chart for GSM1800...................................................................................... 18

Fig 7 Troubleshooting chart for GSM1900...................................................................................... 20

Fig 8 Measurement points at RX frontend - part 1...................................................................... 21

Fig 9 Measurement points at RX frontend - part 2...................................................................... 21

Fig 10 Measurement points at baseband IQ................................................................................... 22

Fig 11 Measurement points at digital IQ......................................................................................... 22

Fig 12 TX RF block diagram.................................................................................................................. 27

Fig 13 Troubleshooting chart of TX-BB interface and control signals .................................... 30

Fig 14 Oscilloscope screen shots........................................................................................................ 30

Fig 15 Troubleshooting chart of RF side of transmitter............................................................... 31

Fig 16 Phoenix set-up (RF Controls menu)......................................................................................35

Fig 17 Phoenix set-up (Tx IQ Tuning menu).................................................................................... 35

Fig 18 Phoenix set-up (Tx IQ Tuning windows).............................................................................. 36

Fig 19 Spectrum analyzer screen shot when performing IQ tuning, part 1........................... 37

Fig 20 Spectrum analyzer screen shot when performing IQ tuning, part 2........................... 38

Fig 21 Phoenix menu select (Tx Power Level Tuning menu)....................................................... 39

Fig 22 Phoenix Power Level Tuning menu .......................................................................................40

Fig 23 Phoenix screen shot (Tx Power Level Tuning).................................................................... 41

Fig 24 Spectrum analyzer screen shot during power level tuning ........................................... 42

Fig 25 Synthesizer block diagram ...................................................................................................... 43

Fig 26 RF key component. .................................................................................................................... 45

Fig 27 Synthesizer key components without shielding frame ...................................................45

Fig 28 Preparation for troubleshooting using Phoenix – RF control setup............................ 46

Fig 29 Troubleshooting chart for synthesizer .................................................................................47

Fig 30 Measurement points for synthesizer. Layout shows HELGO/VCO compartment..... 48

Fig 31 Measurement points for synthesizer. Layout shows UEME compartment................ 48

Fig 32 RH-51/52, RH-67/68 Bluetooth component placement ................................................49

Fig 33 Phoenix settings for Bluetooth troubleshooting............................................................... 51

Fig 34 Bluetooth troubleshooting flowchart .................................................................................. 52

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Nokia Customer Care 6(b) - RF Troubleshooting

Introduction

This document describes troubleshooting and RF tuning of RH-51/52, RH-67/68. In general, two types of measurements have to be done during troubleshooting and repair of phones:

• RF measurements shall be done with a spectrum analyzer, either connected directly to the RF connector of the RF adapter board SA-29, or used together with a highfrequency probe to measure RF signals at points along the TX or RX chain.

• LF (Low-Frequency) and DC measurements shall be done either with a multimeter, or with an oscilloscope together with a 10:1 probe.

All tuning must be done with Phoenix Service Software 2004.32.2.58 or later.

Always make sure that the measurement set-up has been calibrated when measuring RF parameters at the RF connector. Remember to include the correct losses in the module repair jig and the connecting cable when realigning the phone.

Most RF semiconductors are static discharge sensitive. ESD protection must be taken into account during repair (ground straps and ESD soldering irons).

Helgo RF ASIC is moisture sensitive. Therefore, Helgo RF ASIC must be pre-baked prior to soldering unless it is stored in a sealed moisture barrier bag.

RF calibration done via Phoenix software is temperature sensitive because of calibration of 26MHz reference oscillator (VCXO). According to the Helgo specification,

the ambient temperature has to be in the range of 22 to 36°C.

General troubleshooting

Note: In this text the following terms are used interchangeably: GSM900 = EGSM900 = EGSM GSM1800 = DCS band = PCN band GSM1900 = PCS band

The first step of fault-finding should always be a visual inspection. Carefully inspect the RF area using a microscope and look for solder bridges, missing components, short circuits, components that have partially come off and other anomalies. Capacitors can be checked to see that they are not short-circuited, and inductors that they are not open circuits. Also check that power supply lines are not short-circuited, i.e. not 0Ω to ground.

Instruments needed for troubleshooting (minimum requirement):

• oscilloscope

• multimeter

• spectrum analyzer (SA)

Note: Always use an attenuator at the spectrum analyzer input to ensure that the SA will not become damaged by excessive input power from the phone. Check the spectrum analyzer for maximum allowable input power.

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For example, when transmitting in the EGSM band at max power level, the output power will be around +33dBm. By using a 10dB attenuator the actual input to the SA will then be +23dBm. Also adjust the internal attenuator so that the transmitted signal is reduced to less than around -10dBm in order to avoid saturation of SA input stage.

• power supply that can deliver at least 2Adc

• Nokia MJ-25 module jig (also called test jig)

•RF adapter SA-29

• PC with Phoenix installed

• PKD-1 deskey dongle for Phoenix

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Nokia Customer Care 6(b) - RF Troubleshooting

RF key component placement

The following figure shows the key components of the RF section.

Figure 1: RF key components

Z800

Antenna

Switch

N700

Power

Amplifer

Z801

SAW

EGSM900/GSM850

Figure 2: RF key components

V800

LNA

Z191

SAW

GSM1900

GSM1800

13 14

T800

BALUN

Z802

SAW

Z803

SAW

Z700

SAW

T700

BALUN

Z192

BALUN

G500

VCO

N500

Cellular

Transceiver

ASIC

HELGO

G501

TCXO

D190

Bluetooth

Transceiver

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Receiver troubleshooting

General description

Figure 3: Receiver signal path

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Each receiver path is a direct conversion linear receiver. From the antenna, the received RF signal is fed to a front end module where a diplexer first divides the signal to two separate paths according to the band of operation: either lower, GSM850/EGSM900 or upper, GSM1800/1900 path. At each of the paths follows a pin-diode switch, which is used to select either a receive- or transmit mode. At the upper band in the receive mode either GSM1800 or 1900 path is further selected by another pin-diode switch. The selections are controlled by Helgo, which obtains the mode/band and timing information through the RFBus. After the switches an external bandpass filter follows each receiver paths. Thereafter, the signal is fed to the LNA's. GSM850/EGSM900 and GSM1800 LNA's are integrated in Helgo, while the GSM1900 LNA is a discrete component placed between SAW filter and balun. In GSM1900, the amplified signal is fed to a pre-gain stage of the mixer. GSM850/EGSM900 and GSM1800 LNA's are connected directly to the pregain stages. The pregain stages as well as all the following receiver blocks are integrated in Helgo. The LNA's have three gain levels. The first one is the maximum gain, the second one is about 30 dB below the maximum, and the last one is the off state.

After the pregain stages there are demodulator mixers at each signal path to convert the RF signal directly down to baseband I and Q signals. Local oscillator signals for the mixers are generated by an external VCO. The frequency is divided by two in GSM1800 and GSM1900 and by four in GSM850/EGSM900. Those frequency dividers are integrated in Helgo and in addition to the division they also provide accurate phase shifting by 90 degrees which is needed for the demodulator mixers.

The demodulator output signals are all differential. After the demodulators there are amplifiers called DtoS (differential to single ended) which convert the differential signals to single ended. Before that, they combine the signals from the three demodulators to a single path which means that from the output of the demodulators to the baseband interface are just two signal paths (I and Q), which are common to all the frequency bands of operation. In addition, the DtoS amplifiers perform the first part of the channel filtering and AGC (automatic gain control). They have two gain stages, the first one with a constant gain of 12 dB and -3 dB bandwidth of 85 kHz and the second one with a switchable gain of ±6 dB. The filters in the DtoS blocks are active RC filters. The rest of the analog channel filtering is provided by blocks called BIQUAD which include modified Sallen-Key biquad filters.

After the DtoS and BIQUAD blocks, there is another AGC-amplifier which provides a gain control range of 42 dB in 6 dB steps. The correlation between the gain steps and the absolute received power levels is found by a calibration routine in the production for each assembled phone.

In addition to the AGC steps, the last AGC stage also performs the real time DC offset compensation, which is needed in a direct conversion receiver to cancel out the effect of the local oscillator leakage. DC offset compensation is performed during an operation called DCN1. DCN1 is carried out by charging capacitors at the input of the last AGC stages to a voltage, which causes a zero DC offset. To improve the accuracy a DC level alignment possibility has been added to Helgo.

After the last AGC stages the single ended and filtered I- and Q-signals are fed to the RX

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ADCs. The maximum peak-to-peak voltage swing for the ADCs is 1.45 V.

General instructions for RX troubleshooting

Connect the phone to a PC with DAU-9S cable and dongle and follow the following instructions:

Measuring RX I/Q signals using RSSI

Start Phoenix Service Software and establish connection to the phone

Select File -> Open Product

RH-51, -52, -67 or -68

Select Testing ->RF controls

Select Band ->GSM850 / GSM900 / GSM1800 / GSM1900

Active unit ->RX

Operation mode ->Burst

RX/TX channel -> EGSM900: 37

GSM850: 190

GSM1800: 700

GSM1900: 661

Select

Testing (T)

RSSI Reading (R)

Set –up now looks like this:

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Apply a signal with frequency of

EGSM900:942.4677MHz (channel 37 + 67.7KHz offset)

GSM850: 881.667MHz (channel 190 + 67.7KHz offset)

GSM1800:1842.8677MHz (channel 700 + 67.7KHz offset)

GSM1900:1960.0677MHz (channel 661 + 67.7KHz offset)

and a power level of –80dBm to the RF connector (remember to compensate for cable loss).

In RSSI reading, click Read now.

The resulting RSSI level should be –80dBm in each band.

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Measuring RX performance using SNR measurement

Note: This measurements also provides an indication of the conducted sensitivity

Start Phoenix Service Software and establish connection to the phone

Select File ->Open Product

RH-51, -52, -67 or -68

Select Testing ->RF controls

Select Band ->GSM850 / GSM900 / GSM1800 / GSM1900

Active unit ->RX

Operation mode ->Burst

RX/TX channel -> EGSM900: 37

GSM850: 190

GSM1800: 700

GSM1900: 661

Select Testing (T)

SNR Measurement (M)

select Both

Choose respective band (GSM850, EGSM900, GSM1800, GSM1900).

Press Start.

Follow the instructions for Signal generator set–up in the pop–up window.

Press OK.

Read the SNR result. SNR should be: >18dB.

Check the sensitivity value.

The set–up should now look like this; the icon also includes pop–up window for reference:

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Measuring the RX module manually using oscilloscope and spectrum analyzer

Spectrum analyzer level values depend on the probe type and should be validated using a known good sample. The levels that are given here are measured using a high frequency probe.

Measuring with oscilloscope at test point RXI (J827) or RXQ (J828) ) and RXID (J261) or RXQD (J262) is recommended only if RSSI reading does not provide enough information.

GSM 900/850

Start Phoenix Service Software and establish connection to the phone

Select File Open Product

RH-51, -52, -67 or -68

Select Testing RF controls

Select Band GSM900 (GSM850)

Active unit RX

Operation mode Continuous *

RX/TX channel 37 (190 for GSM850)

AGC 12

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Input freq/level of signal generator is 942.4677MHz, -60dBm

(881.6677MHz for GSM850)

Note: Because DC compensation doesn’t work during continuous mode, DC offset level at RXI and RXQ will gradually shift from the optimized level. To have most reliable result, it is highly advisable to set operation mode from burst to continuous just before measuring values and complete measurement within no longer than 30 seconds.

Figure 4: Troubleshooting chart for EGSM900 (GSM850)

EGSM900 (GSM850)

chain functional

Replace UPP

D370

942.4677 MHz (881.6677 MHz for GSM850)

YES

Apply -60 dBm

from generator to antenna connector

Check RSSI using

Phoenix Does it

match Sig Gen

Output level ?

Is L.O running at

3769.6MHz

(3526.4MHz for

GSM850?

YES

Probe J827, 828

RX I &Q Does waveform

look like example given

earlier ?

YES

Probe J261 &J263 Is digital data visable ?

Replace UEM

D250

Refer to Synthesiser

Fault -finding chart

Check RX/TX switch

at RX 900 Z800

Input -63 dBm

Output -63dbm

YES

Spectrum analyzer

EGSM SAW filter

Z803

output -66 dBm

YES

NO NO

Oscilloscope

check Vc1, Vc2, Vc3

at Z800 signal 0V

YES

Check

RX/TX switch

Z800

Check SAW filter

Z803

Check HELGO

N500

Spectrum analyzer

Check signal after

inductors L804 and

L805

-66 dBm YES

Oscilloscope

VR4 2.7 V

on N500

YES

Check inductors

L804, L805

Check UEM

D250

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Figure 5: Probed RX I/Q signals J827, 828

Signal amplitude 180 ~ 600mVpp

DC offset 1.2 ~ 1.4V

Frequency approx 67KHz

GSM1800

Start Phoenix Service Software and establish connection to the phone.

Select File Open Product

Select Testing RF controls

Select Band GSM1800

Active unit RX

Operation mode Continuous *

RH-51, -52, -67 or 68

RX/TX channel 700

AGC 12

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Input freq/level of signal generator is 1842.8677MHz, -60dBm

Figure 6: Troubleshooting chart for GSM1800

Apply -60 dBm

1842.8677 MHz

from generator to antenna

connector

Check RSSI using

YES

GSM1800 chain

functional

Phoenix Does it

match Sig Gen

Outp u t le v e l ?

Replace UPP

D370

Is L.O running at

3685.6MHz?

YES

Probe J827,828

RX I &Q Does wave fo rm lo o k

like example given earlier ?

YES

Probe J261 &J263

Is digital data

visable ?

Replace UEM

D250

Refer to Synthesiser

Fault -finding chart

Check RX/TX sw itch

at RX 1800 Z800

Input -63 dBm

Output -65dBm

Spectrum analyzer GSM1800

SAW filter Z802 output -70 dBm

Spectrum analyzer

Check signal after inductors

L802 and L803

Oscilloscope

VRX 2.7 V on HELGO

YES

-73 dBm

YES

N500

NO NO

Oscilloscope

check Vc1, Vc2, Vc3

at Z800 signal 0V

YES

Check RX/TX switch

Z800

Check S A W filter

Check inductors

L802, L803

Check UEM

Z802

D250

Check HELGO

N500

YES

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GSM1900

Start Phoenix Service Software and establish connection to the phone.

Select File Open Product

RH-51, -52, -67 or -68

Select Testing RF controls

Select Band GSM1900

Active unit RX

Operation mode Continuous *

RX/TX channel 661

AGC 12

Input freq/level of signal generator is 1960.0677MHz, -60dBm

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Figure 7: Troubleshooting chart for GSM1900

Apply -60 dBm

1960.0677 MHz

from generator to antenna

connector

YES

GSM1900 chain

functional

Check RSSI using

Phoenix Does it

match Sig Gen

Output level ?

Is L.O running at

3920.0MHz?

Refer to Synthesiser

Fault -finding chart

Check RX/TX switch

Z800

Replace UPP

D370

Probe J827,828

RX I &Q Does waveform look

like example given earlier ?

YES

Probe J261 &J263 Is digital data visable ?

Replace UEM

D250

YES

Check RX/TX switch

at RX 1900 Z800

Input -63 dBm

Output -65 dBm

YES

Spectrum analyzer

GSM1900 SAW filter

Z801

output -70 dBm

YES

Spectrum analyzer

Check signal after

LNA V800

-55 dBm

YES

Spectrum analyzer

Check signal after

balun T800

-56 dBm

YES

Spectrum analyzer

Check signal after capacitor s

C805 and C806

-56 dBm

YES

NO NO

Oscilloscope

check Vc1, Vc2, Vc3

at Z800 signal Vc1,

Vc3 =0V

Vc2=2.7V

Check SAW filter

Z801

Check V800

Check balun

T800

Check

C805, C806 and

L807

Check HELGO

N500

Oscilloscope

VR4 2.7 V

on N500

YES

Check UEM

D250

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Measurement points in the receiver

Figure 8: Measurement points at RX frontend - part 1

L802, 803

output

L804, 805

GSM1900

out

Z803

output

V800

output

Z800

output

Z801

out

Z802

out

Figure 9: Measurement points at RX frontend - part 2

C805, 806

out

T800

output

Z800 VC2

Z800 VC1

Z800

GSM1800

output

Z800 EGSM900 (GSM850)

output

Z800

input

Z800 VC3

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Figure 10: Measurement points at baseband IQ

J827 RXI

J828

RXQ

Figure 11: Measurement points at digital IQ

J261

RXID

J262

RXQD

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Tuning RX using Phoenix

RX channel select filter calibration

This calibration calibrates the baseband filter inside Helgo ASIC. It is done by internally measuring a prototype filter, for this reason the calibration is done once, not separately 3

bands.

This tuning doesn’t require RF input from an external signal generator.

Select Tuning RX Channel Select Filter Calibration

Check “Save to Phone”

Press Tune

Press Stop to store the data to the phone.

RX channel select filter calibration is finished.

RX calibration

The "RX calibration" is used to determine gain at different gain settings for front-end and the Helgo ASIC and needs to be done in all three bands.

RX calibration requires an external signal generator.

Select Tuning RX calibration

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Check Automatic calibration mode.

Check load from phone and Save to phone.

Press Start

Initial data will be loaded from the phone and calibration starts.

You will see following banner pops up.

Follow the instructions in the pop–up window and set frequency and level of the signal generator

Press OK

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Press “Save & Continue”

Calibration data will be stored to the phone and continue to the next band.

RX band filter response compensation

Rx band filter response compensation has 9 steps for each band.

Rx band filter response compensation requires an external signal generator.

Select Tuning RX Band Filter Response Compensation

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Select Manual Tuning mode

Press Start.

Initial data will be loaded from the phone.

Press tune to start calibration.

Follow the instructions given in the following pop–up window and set frequency and level of the signal generator.

Press OK to proceed to the next step.

After completely the 9 steps –calibration at 9 frequencies.

Test will be repeated for other bands.

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Transmitter troubleshooting

General description

A simple block diagram of the TX part of the phone is shown in the following figure. The voice or data signals to be transmitted come from the UEME IC in the BB (baseband) area, and go to the Helgo IC, where they are up-converted to RF. The TX signals going from UEME to Helgo are called the IQ-signals, and consist of two balanced signals { TXIN, TXIP } and { TXQN, TXQP }, i.e. a total of four signal lines. In addition to the IQ signals, there are also control signals going between BB and RF.

Figure 12: TX RF block diagram

BB-RF

Interface

Signals:

From UEME:

TXIQ

Helgo

V_BAT

1800 / 1900MHz

Ant-Switch

1/2

900MHz

RFBusClk RFBusEna1 RFBus Data Reset

1/4

Synthesizer

(LO=Local Oscillator)

VPCTRL_900

VPCTRL_1800_1900

SAW

Power Loop Filter

DET

The following picture shows the two shielding cans where the TX circuitry is located (the lids have been removed). The upper shielding can contains BB-RF interface circuitry, the Helgo RF system IC, a SAW filter for the GSM/EGSM band, and a balun for the DCS/PCS band. The lower shielding can contains the power amplifier (PA) and the antenna switch module (ASM).

RH-51/52, RH-67/68 Company Confidential 6(b) - RF Troubleshooting Nokia Customer Care

(E)GSM

SAW filter

Helgo

DCS/PCS

Balun

Preparation for troubleshooting

• Place the phone (mechanics removed) on module jig.

• Connect the module jig to the PC via a DAU-9P cable.

• Connect the module jig to a power supply (4.2V).

• Connect the RF output to a spectrum analyzer or another measurement instrument. Use a 10dB attenuator at the input to spectrum analyzer to avoid damaging it.

• Make sure the dongle is connected and start Phoenix.

• In Phoenix: File → Open Product → RH-51, -52, -67 or -68 Product Menu.

• Select Testing → RF Controls.

• From the toolbar: set Operating Mode to Local.

• Select band ‘GSM850’ ‘GSM900’, ‘GSM1800’ or ‘GSM1900’.

• Set Operation Mode to Burst.

ASM

Power

Amplifier

• Set Active Unit to Tx.

• Set Tx Data Type to All 1.

• Set Rx/Tx Channel to 190 for GSM850, 37 for GSM900, 700 for GSM1800 or 661 for GSM1900.

• Set Tx PA Mode to Free.

• Set Tx Power Level to 5 in GSM850/GSM900, otherwise to 0.

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Nokia Customer Care 6(b) - RF Troubleshooting

Phoenix should now look like this:

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Fault-finding chart: TX-BB interface and control signals

Figure 13: Troubleshooting chart of TX-BB interface and control signals

TXC-signal

EGSM900

channel = 37

PL = 5

Figure 14: Oscilloscope screen shots

Typical oscilloscope plots

of the four TXIQ-line s:

zoom

1.1Vdc

TXP-signal

~67kHz

0.5Vpp

waveform for all 1's

4.615ms

VTXB_900

2.7V

Ctrl signals to ASM:

( DCS/PCS )

Cont1

Cont2

4.615ms

2.7V

4.615ms

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Fault-finding chart: RF side of transmitter

Figure 15: Troubleshooting chart of RF side of transmitter

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ASM

Output

850/900

Output

PA 1800/ 1900

Output

PA 1800/ 1900 Input

PA 850/

900 Input

VPCTRL 1800_1900

VBAT

VPCTRL 900

UPP

D370

J813

D190

TXP

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RH-51/52, RH-67/68 Company Confidential 6(b) - RF Troubleshooting Nokia Customer Care

Transmitter tuning

In the transmitter there are two kinds of tunings that can be done; IQ tuning and power level tuning. In general, different repairs require different tunings. In order to decide which tuning is necessary after a repair, it is important to understand well the functionality of the repaired circuit. In general, it is recommended that if any TX component is changed, both these tunings be done. All tunings are done in local mode, and using Phoe- nix to control the phone.

In addition to that, note that the product has two different variants; RH-51, -67 (GSM900/GSM1800/GSM1900) and RH-52, -68 (GSM850/GSM1800/GSM1900), and please proceed the tuning with corresponding bands for those variants. In this document, some examples are described using GSM900 case, however please replace its description as GSM850 if you handle the RH-52, -68 variant.

Also, as the RH-51/52, RH-67/68 doesn’t support EDGE feature, you don’t need to consider operating / tuning the phones in EDGE mode although Phoenix sometimes has a control selectional box to enable EDGE.

TX IQ tuning

The tuning must be carried out in all three bands. In addition to Phoenix, a spectrum analyzer (SA) is needed. Connect the SA to the RF connector of the module jig. The settings of the spectrum analyzer will depend on the band to be tuned. The following table summarizes the settings for each of the three bands.

Table 1: Spectrum analyzer settings

GSM850 GSM900 GSM1800 GSM1900

Center frequency 836.6MHz 897.4MHz 1747.8MHz 1880MHz

Frequency span 300kHz 300kHz 300kHz 300kHz

Resolution Bandwidth 3kHz 3kHz 3kHz 3kHz

Video Bandwidth 3kHz 3kHz 3kHz 3kHz

Sweep Time 3 sec 3 sec 3 sec 3 sec

Trace Type Clear/Write Clear/Write Clear/Write Clear/Write

Detector Type Max Peak Max Peak Max Peak Max Peak

Reference Level 35dBm 35dBm 35dBm 35dBm

Marker 1 836.53229 MHz 897.33229 MHz 1747.73229 MHz 1879.93229 MHz

Marker 2 836.6 MHz 897.4MHz 1747.8MHz 1880MHz

Marker 3 836.66771 MHz 897.46771MHz 1747.86771MHz 1880.06771MHz

For this tuning, two windows of Phoenix must be open: (1) Testing → RF Controls, and (2) Tuning → TX IQ Tuning, as seen in figures below.

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Figure 16: Phoenix set-up (RF Controls menu)

Figure 17: Phoenix set-up (Tx IQ Tuning menu)

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After opening the two before-mentioned windows, Phoenix should look like this:

Figure 18: Phoenix set-up (Tx IQ Tuning windows)

The following table summarizes the settings of the RF control window for IQ tuning of the three bands.

Table 2: RF Control window settings

Band TX Data Type TX Power Level RX/TX Channel

GSM850 All 1 5 190

GSM900 All 1 5 37

GSM1800 All 1 0 700

GSM1900 All 1 0 661

To start the IQ tuning, press the ‘Start’ button in the IQ tuning window.

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Figure 19: Spectrum analyzer screen shot when performing IQ tuning, part 1

Ref Lvl

35 dBm

27.5 dB Offset

Marker 1 [T1]

33.35 dBm

897.33229000 MHz

RBW 3 kHz

VBW 3 kHz

SWT 3 s

1 [T1] 33.35 dBm

897.33229000 MHz

2 [T1] -6.76 dBm

897.40000000 MHz

3 [T1] -10.74 dBm

897.46771000 MHz

RF Att 30 dB

Unit dBm

-10

-20

-30

-40

-50

-60

-6

Date: 14.JAN.2002 13:11:55

The purpose of this tuning is to reduce the frequency components at marker 2 (carrier leakage) and marker 3 (+67kHz / upper sideband) as much as possible. Adjust the ‘TXI DC Offset’ and the ‘TXQ DC Offset’ buttons in the TX IQ Tuning window so that the carrier level (marker 2) reaches a minimum. After this adjustment is done, the carrier (marker 2) should be at least 40dB below the lower side band (marker 1).

30 kHz/Center 897.4 MHz Span 300 kHz

Next, use the ‘Amplitude difference’ and the ‘Phase difference’ buttons in the TX IQ Tuning window to adjust the upper side band (marker 3) to a minimum. Now, marker 3 should also be at least 40dB below marker 1.

At this point, the spectrum analyzer screen should look similar to that of the figure below.

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Figure 20: Spectrum analyzer screen shot when performing IQ tuning, part 2

Ref Lvl

35 dBm

Ref Lvl

35 dBm

27.5 dB Offset

-10

-20

-30

-40

-50

-60

-65

e: 14.JAN.2002 13:23:02

Date: 14.JAN.2002 13:23:02

33.40 dBm Marker 1 [T1]

897.33229000 MHz

33.40 dBm

897.33229000 MHz

VBW 3 kHz

RBW 3 kHz

SWT 3 s

VBW 3 kHz

SWT 3 s

897.33229000 MHz

897.40000000 MHz

897.46771000 MHz

>40dB

suppression

1 [T1] 33.40 dBm

2 [T1] -20.35 dBm

897.33229000 MHz

3 [T1] -27.60 dBm

897.40000000 MHz

897.46771000 MHz

RF Att 30 dB

Unit dBm

1 [T1] 33.40 dBm

2 [T1] -20.35 dBm

3 [T1] -27.60 dBm

suppression

30 kHz/Center 897.4 MHz Span 300 kHz

After reducing the amplitude of the frequency components at marker 2 and 3 to a minimum, press ‘Save & Continue’. The EGSM tuning has now been completed.

Now, using the spectrum analyzer settings listed in Table “Spectrum analyzer settings” and the RF control settings listed in Table “RF Control window settings”, follow exactly the same procedure to perform IQ tuning in the GSM1800 and GSM1900 bands.

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TX power level tuning

This tuning is done separately in all three bands, and requires a spectrum analyzer to measure the burst power of the GSM RF signal. When measuring the RF output (burst) power on a spectrum analyzer, use the settings found in the following table:

Table 3: Spectrum analyzer settings for Tx power level tuning

GSM850 GSM900 GSM1800 GSM1900

Center frequency 836.6MHz 897.4MHz 1747.8MHz 1880MHz

Frequency span Zero-span Zero-span Zero-span Zero-span

Resolution Bandwidth 1MHz 1MHz 1MHz 1MHz

Video Bandwidth 1MHz 1MHz 1MHz 1MHz

Sweep Time 1ms 1ms 1ms 1ms

Trigger Type Video Video Video Video

Video trigger level Target pwr – 10dB Target pwr – 10dB Target pwr – 10dB Target pwr – 10dB

Trace Type Clear/Write Clear/Write Clear/Write Clear/Write

Detector Type Max Peak Max Peak Max Peak Max Peak

Reference Level Target power level +

10dB

Internal Attenuation Target power level +

10dB

Target power level + 10dB

In Phoenix, select Tuning → TX Power Level Tuning

Figure 21: Phoenix menu select (Tx Power Level Tuning menu)

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Phoenix should now look similar to the figure below.

Figure 22: Phoenix Power Level Tuning menu

Connect the module jig RF output to the measurement instrument. The power must be tuned in only high TX PA mode in all bands of GSM850, GSM900, GSM1800 and GSM1900.

For each band, tune the power by adjusting the coefficient in the ‘Tx Power Level Tuning’ window in Phoenix until the target level is reached (measured on the spectrum analyzer). Remember to take into account the external power loss, i.e. the loss of the cable and the external attenuator at the spectrum analyzer input.

The coefficient must be tuned for the base level and other levels marked with bold letters in Phoenix (GSM850/GSM900: PL19 / 15 / 5, GSM1800/1900: PL15, 11, 0). The target power levels are specified as listed in the following table:

Table 4: Spectrum analyzer settings for Tx level tuning

GSM850 GSM900 GSM1800 GSM1900

LV5 32.5dBm LV5 32.5dBm LV0 30.0dBm LV0 30.0dBm

LV15 13.0dBm LV15 13.0dBm LV11 8.0dBm LV11 8.0dBm

LV19 5.0dBm LV19 5.0dBm LV15 0.0dBm LV15 0.0dBm

Base -27.0dBm Base -27.0dBm Base -27.0dBm Base -27.0dBm

When the tuning for the levels marked with bold letters has been completed, press ‘Cal-

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culate coefficients’ to calculate the other power levels with non-bold letters.

When the coefficient calculation was done successfully, then press ‘Save & Continue’ to save the new tuning values into the phone memory.

The following figure shows the power level tuning at the GSM900 band.

Figure 23: Phoenix screen shot (Tx Power Level Tuning)

The figure below shows one example from the spectrum analyzer screen during measuring the Tx power level.

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Figure 24: Spectrum analyzer screen shot during power level tuning

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Synthesizer troubleshooting

General description

Figure 25: Synthesizer block diagram

RFBusData

RFBusClk

AFC

8%1

NQQR

HKNVGT

/*\

RFBusEna1

Reset

RFCLK

LPRFCLK

1/2

PLL_BLOCK

1/4

EJCTIG

0&+8

RWOR

#&+8



4&+8

1/2

CNTROL

1/4

‡”

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The PLL is capable of tuning frequency range for GSM band 850/900/1800/1900. Hence PLL is common in all variants.

The VCO frequency is locked by a PLL (phase locked loop) into a stable frequency source given by a VCTCXO, which is running at 26 MHz. The frequency of the VCTCXO is in turn locked into the frequency of the base station with the help of an AFC (automatic frequency control) voltage, which is generated in UEME by an 11-bit D/A (digital-to-analog) converter.

The PLL is integrated in Helgo and it is controlled through the RFBus. The PLL consists of a 64/65 (P/P+1) prescaler, N- and A-divider, reference divider, phase detector and a charge pump for the external loop filter. The 4 GHz oscillator signal, generated by the VCO, is fed through a 180 degrees balanced phase shifter to the prescaler and the output of the prescaler is fed to the N- and A-divider, which produces the input to the phase detector. The phase detector compares this signal to the reference signal, which is divided by the reference divider from the VCTCXO frequency. The frequency of the reference signal is 400 kHz. The output of the phase detector is connected to the charge pump, which charges or discharges the integrator capacitor in the loop filter depending on the phase of the measured frequency compared to the reference frequency. The integrator output voltage is finally connected to the control input of the VCO. The VCO operates at the channel frequency multiplied by two in DCS1800/PCS1900 and by four in GSM850/EGSM900. The required frequency dividers for modulator and demodulator mixers are integrated in Helgo.

Loop filter filters out the comparison pulses of the phase detector and generates a DC control voltage to the VCO. The loop filter determines the step response of the PLL (settling time) and contributes to the stability of the loop. Other filter components are for sideband rejection. The dividers are controlled via the RFBus. RFBusData is for the data, RFBusClk is a serial clock for the bus and RFBusEna1X is a latch enable, which stores the new data into the dividers.

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Figure 26: RF key component.

VCTXO 26MHz G500

Balun 3-4GHz T500

VCO 3-4GHz G500

Assumption

Figure 27: Synthesizer key components without shielding frame

No failure i.e. soldering or component failure for simple SMD components such as resistors, inductors and capacitors.

Failure in one particular operating GSM channel whether Tx or Rx in which the synthesizer is the cause of the failure, all other GSM channel in Tx/Rx should fail.

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Preparation for troubleshooting

• Place the phone (mechanics removed) on module jig.

• Connect the module jig to the PC via a DAU-9P cable.

• Connect the module jig to a power supply (4.2V).

• Connect the RF output to a spectrum analyzer or another measurement instrument.

• Use a 10dB attenuator at the input to spectrum analyzer to avoid damage.

• Make sure the dongle is connected and start Phoenix.

• In Phoenix: File → Open Product → RH-51, -52, -67 or -68 Product Menu.

• Select Testing → RF Controls.

• From the toolbar: set Operating Mode to Local.

• Select band “GSM 1800”.

• Set Operation Mode “Continuous”.

• Set Active Unit “Rx”.

• Set Rx/Tx Channel “700”.

Figure 28: Preparation for troubleshooting using Phoenix – RF control setup.

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Measuring the synthesizer manually using spectrum analyzer

Spectrum analyzer level values depend on the probe type and should be validated using a known good sample. The levels that are given here are measured using a high frequency probe. Spectrum analyzer should be at least capable of measuring signal upto 4.5 GHz.

Troubelshooting chart for synthesizer

Figure 29: Troubleshooting chart for synthesizer

LOCAL OSCILLATOR

FAILURE

YES

Check

VCTXCO Output

min. 0.7p-p clipped sinewave

26MHz

Check

VR1=Vcp=4.6-4.9V

VR5=Vpre=2.6-2.9V

Check

VR7=VCO Vcc=2.6-2.9V

Remove

HELGO/VCO

Shielding

Frame

NOK

Replace VCTXCO

G501

Check

VCTCXO

Vcc=2.6-2.9V

Replace UEME

D250

Replace UEME

D250

NOK

Replace VCTXCO

G501

NOK

Replace UEME

D250

Replace HELGO

N500

Replace HELGO

N500

VCO Output

Freq=3685.6Mhz

Power=-25 to-10dBm

Replace UEME

D250

Probe

NOK

Replace VCO

G500

NOK

Probe

VCO Output

Freq=3.0 to 4.5GHz

Power=-25 to-10dBm

Probe Balun +/- output

Freq=3.0 to 4.5GHz

Power=-30 to-10dBm

Replace HELGO

N500

NOKNOK

NOK

Replace VCO

G500

Replace

Attenuator&Balun

R503&T500

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Figure 30: Measurement points for synthesizer. Layout shows HELGO/VCO compartment.

C526 VCTCXO Vcc

G501 VCTCXO Output

HELGO N500

Balun +/- Output T500

Figure 31: Measurement points for synthesizer. Layout shows UEME compartment

UEME D250

G516 VR1=Vcp

C517 VR5=Vpre

G500 VCO RF Output

C301 VR7=VCO Vcc

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Bluetooth troubleshooting

This document describes BC02 bluetooth solution troubleshooting for Care. Applicable parts can be copied to phone products’ service document. It is assumed that the main service manual includes part “How to connect Phoenix to phone”.

Bluetooth component placement

Figure 32: RH-51/52, RH-67/68 Bluetooth component placement

Bluetooth settings for Phoenix

Procedure:

1 Connect phone to Phoenix in ‘local’ mode.

2 Select product by: File −> Scan Product.

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3 Choose: Testing −> Bluetooth LOCALS

4 Locate JBT-9’s Ser.No. (12 digits from the type label) found in the type label in

the back of JBT-9.

5 In the Bluetooth LOCALS setting enter Ser.No. for the “Counterpart Device

Address” field. This has to be done only once provided JBT-9 is not changed.

6 Run BER test when JBT-9 box is proximity of the DUT’s Bluetooth antenna. Suit-

able distance is approximately 10 centimeter.

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Figure 33: Phoenix settings for Bluetooth troubleshooting

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Bluetooth troubleshooting diagram

Figure 34: Bluetooth troubleshooting flowchart

Bluetooth fault

Replace BC02

(D190)

Connection to

JBT9 OK ?

Is BC02 VREG_IN =

2.8V at C203?

Is BC02 VDD_ANA

= 1.8V at C201

BER <=

0.1%?

Bluetooth ok

Vflash1 from

UEME not

supplied

Check component

soldering in RF path

(Z191, Z192, C191,

C192, L191, L192)

Replace balun

and filter

(Z191, Z192)

Replace BC02

(D190)

Replace

inverter (D191)

Reference clock

from HELCO not

supplied

Is BC02 Xtal_in

(1) frequency = 26MHz

(2) voltage swing = about

1000mV

Nokia 6670, 7610 Service Manual 06b rh51 rf trouble

Specifications and Main Features

Frequently Asked Questions

User Manual

Introduction

General troubleshooting

RF key component placement

Receiver troubleshooting

General description

General instructions for RX troubleshooting

Measuring RX I/Q signals using RSSI

Measuring RX performance using SNR measurement

Measuring the RX module manually using oscilloscope and spectrum analyzer

GSM 900/850

GSM1800

GSM1900

Measurement points in the receiver

Tuning RX using Phoenix

RX channel select filter calibration

RX calibration

RX band filter response compensation

Transmitter troubleshooting

General description

Preparation for troubleshooting

Fault-finding chart: TX-BB interface and control signals

Fault-finding chart: RF side of transmitter

Transmitter tuning

TX IQ tuning

TX power level tuning

Synthesizer troubleshooting

General description

Assumption

Preparation for troubleshooting

Measuring the synthesizer manually using spectrum analyzer

Troubelshooting chart for synthesizer

Bluetooth troubleshooting

Bluetooth component placement

Bluetooth settings for Phoenix

Bluetooth troubleshooting diagram