Nokia N-GageQDa Service Manual 07 rh47 RF.book

Nokia Customer Care

RH-47 Series Cellular Phones

7 - RF Description and

Troubleshooting

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Page No

Abbreviations............................................................................................................................................ 5

Introduction to RF ................................................................................................................................... 6

RF power supply configuration .........................................................................................................9

General specifications of transceiver RH-47 ..............................................................................10

Introduction to RF Troubleshooting ................................................................................................ 11

Printed Wired Board ............................................................................................................................ 12

RF key component placement .........................................................................................................12

RF test points .......................................................................................................................................13

Test points RF supply voltages.................................................................................................... 14

RF test points Mjoelner chamber............................................................................................... 15

RF test points VCO chamber........................................................................................................ 15

RF test points PA chamber........................................................................................................... 16

Test points BB area......................................................................................................................... 16

Receiver Troubleshooting ................................................................................................................... 17

General instructions for RX troubleshooting ..............................................................................17

Measuring RX I/Q signals using RSSI reading ........................................................................ 17

Measuring RX performance using SNR measurement ......................................................... 18

Measuring front-end power levels using spectrum analyzer............................................. 20

Measuring analogue RX I/Q signals using oscilloscope....................................................... 21

Receiver troubleshooting .................................................................................................................22

Rx signal paths ....................................................................................................................................23

Antenna switch (RX/TX Switch).................................................................................................. 24

RX front-end .................................................................................................................................... 24

RX paths of Mjoelner RF ASIC..................................................................................................... 25

Transmitter ............................................................................................................................................. 26

General instructions for TX troubleshooting ..............................................................................26

TX signal paths ....................................................................................................................................26

Antenna switch (TX/RX switch) .................................................................................................. 28

GSM850 transmitter ..........................................................................................................................28

General instructions for GSM850 TX troubleshooting......................................................... 28

Troubleshooting for GSM850 transmitter ............................................................................... 29

GSM1900 (PCS) transmitter ............................................................................................................31

General instructions for GSM1900 TX troubleshooting ...................................................... 31

Troubleshooting for GSM1900 transmitter............................................................................. 32

Synthesizer ............................................................................................................................................. 35

General instructions for synthesizer troubleshooting ..............................................................35

Checking synthesizer operation .....................................................................................................35

26 MHz reference oscillator (VCXO) .............................................................................................36

VCO .........................................................................................................................................................37

Troubleshooting for PLL synthesizer .............................................................................................37

Frequency lists .....................................................................................................................................39

GSM850............................................................................................................................................. 39

GSM1900 .......................................................................................................................................... 40

DC Supply Current Check ................................................................................................................... 42

Phoenix Tunings after Repairs .......................................................................................................... 43

APPENDIX A: FLALI Test Cases with Hints for Repair................................................................. 44

APPENDIX B: FINUI Test Cases with Hints for Repair ................................................................ 50

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APPENDIX C: Component Placement with Test Points & Detailed Description.................. 59

APPENDIX D: Calibration of the DA-17/JXS-2 jig, Autotuning and BT Testing.................. 65

Requirements .......................................................................................................................................65

Calibration Problems .........................................................................................................................65

Active calibration: basic idea ..........................................................................................................65

Calibration procedure setup MJ-21 ..............................................................................................65

Data acquisition MJ-21 ....................................................................................................................66

MJ-21 TX power measurement ......................................................................................................67

MJ-21 GSM850 power measurement ..........................................................................................67

MJ-21 GSM1900 power measurement ........................................................................................68

MJ-21 receiver RSSI measurement ...............................................................................................68

MJ-21 RSSI procedure ......................................................................................................................68

MJ-21 RSSI values .............................................................................................................................69

MJ-21 example figures .....................................................................................................................70

JXS-2 / DA-17 “blackbox” setup ....................................................................................................70

Data acquisition JXS-2 / DA-17 .....................................................................................................70

DA-17/JXS-2 example figures ........................................................................................................71

Setting cable loss for Auto-Tuning ...............................................................................................71

Setting DA-17/JXS-2 calibration loss ...........................................................................................72

Assigning the product to the jig ....................................................................................................73

GPIB Setup for Autotuning ..............................................................................................................73

Autotuning ...........................................................................................................................................74

Bluetooth test setup ..........................................................................................................................75

Bluetooth testing ................................................................................................................................75

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Abbreviations

BB Baseband

PCS GSM1900

GSM GSM850

ESD Electro Static Discharge

GPRS General Packed Radio Service

HSCSD High Speed Circuit Switched Data

LNA Low Noise Amplifier

LO Local Oscillator

PA Power Amplifier

PWB Printed Wired Board

PLL Phase Locked Loop

RF Radio Frequency

RX Receiver

SA Spectrum Analyzer

TX Transmitter

VCO Voltage Controlled Oscillator

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Introduction to RF

The RF front-end is a dual-band direct conversion transceiver. Using direct conversion, no intermediate frequencies are used for up- or down -conversions.

The VCO oscillates on the doubled respectively quadruplicated frequency of the wanted RX or TX frequency, depending on the band used. The VCO frequency is divided by either 2 or 4 and fed to the mixers (down-conversion) or modulators (up-conversion). Up- or down-conversion is done in one step, directly between RF frequency and base band. All up- and down-conversion takes place in the RF ASIC named Mjoelner (N601).

Mjoelner RF ASIC also contains PLL and LNAs for all used bands. ADC control section is included to power and/or control GSM850 TX buffer, detector and antenna switch. The Mjoelner RF ASIC is controlled via a serial bus.

Mjoelner RF ASIC contains an integrated VCXO which uses an external 26 MHz Xtal. No analogue AFC signal is needed. AFC is realized via the serial interface port of Mjoelner.

The UPP is supplied by the 26 MHz reference clock of Mjoelner.

The phone supports GPRS (General Packet Radio Service), meaning multi-slot operation. This will not require special equipment or procedures in repair situations.

The following diagrams show the RF frequency scheme and the RF block diagram.

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Figure 1: RF frequency scheme

869 - 894

MHz

1930 - 1990

MHz

F/4

F/2

F/4F/2

PLL

MHz

3296

- 3980 MHz

X-

tal

26 MHz

BB clk

824 - 849

MHz

1850 - 1910

MHz

Mjoelner

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Figure 2: RF block diagram

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RF power supply configuration

All power supplies for the RF Unit are generated in the UEM IC (D190). All RF supplies can be checked either in Mjoelner or in BB chamber.

The power supply configuration used is shown in the block diagram below. Values of voltages are given as nominal outputs of UEM. Currents are typical values.

Figure 3: RF power distribution diagram

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General specifications of transceiver RH-47

Parameter Unit

Cellular System GSM850, GSM1900

RX Frequency Band GSM850: 869 … 894 MHz

GSM1900: 1930 … 1990 MHz

TX Frequency Band GSM850: 824 … 849 MHz

GSM1900: 1850 … 1910 MHz

Output Power GSM850: +5 … +33 dBm (3.2 mW … 2 W)

GSM1900: +0 … +30 dBm (1.0 mW … 1 W)

Duplex Spacing GSM850: 45 MHz

GSM1900: 80 MHz

Number of RF Channels GSM850: 124

GSM1900: 299

Channel Spacing 200 kHz (each band)

Number of TX Power Levels GSM850: 15

GSM1900: 16

Sensitivity, static channel GSM850: -102 dBm

GSM1900: -102 dBm

Frequency Error, static channel < 0.1 ppm

RMS Phase Error < 5.0 °

Peak Phase Error < |20.0 °|

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Introduction to RF Troubleshooting

This document shall provide instructions, how to check, repair and calibrate RH-47 phones. It is assumed, that the phones are disassembled and tested within a repair jig MJ-21.

The following types of measurements have to be done for repair of the phone boards:

• RF measurements are made by using a Spectrum Analyzer together with a highfrequency probe (i.e. hp 85024A Note, that signal levels are not accurate ). Correct attenuation can be checked using a “good” phone board for example.

• LF (Low frequency) and DC measurements are made with an oscilloscope together with a 10:1 probe.

• For receiver measurements a signal generator with frequencies up to 2000 MHz is required. Most of the radio communication testers like CMD55 or CMU200 can be used as signal generator. The signal generator is connected to the antenna port using the repair jig MJ-21.

• Output level measurements of the transmitter are made with a power meter or a calibrated spectrum analyser, which is connected to the antenna port using the repair jig MJ-21.

Always make sure that the measurement set-up is calibrated when measuring RF parameters at the antenna port. Remember to include the correct losses of 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).

Mjoelner RF ASIC is moisture sensitive. Therefore, Mjoelner RF ASIC must be pre-baked prior to soldering.

Rx calibration done via Phoenix software is temperature sensitive because of calibration of the 26 MHz reference oscillator (VCXO). According to Mjoelner specification ambient temperature has to be in a range from 22°C to 36°C.

Apart from key-components described in this document there are a lot of discrete components (resistors, inductors and capacitors) for which trouble shooting is done by checking its proper soldering and complete assembly on the PWB. Capacitors and resistors can be checked by means of an LCR meter, but be aware in-circuit measurements should be evaluated carefully.

In the following GSM850 will be used for the low band, and PCS or GSM1900 for the high band.

Note: In this document there are example measurements being depicted with Phoenix Internal Service Software A2003.42.1.48 pictures.

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Printed Wired Board

RF key component placement

Figure 4: RF key component placement

Description / Part Code Manufacturer’s code NMP Code Supplier

Dual band PA (N801) PF08130B-TB 4350403 Renesas

Mjölner RF ASIC F7 (N601) 4380013 Infineon

BT202i (N430) 0700085 Murata

UHF VCO (G701) ENFVJSW2S08 4350431 Matsushita

UHF VCO Balun (T702) LDB213G6010C-001 4550187 Murata

1900 Tx Balun (T701) LDB211G8005C-001 4550191 Murata

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1900 Rx SAW (Z603) 4511325 Murata

850 Tx SAW (Z701) 4511317 Murata

850 Rx SAW (Z604) 4511323 Murata

Antenna switch (Z601) LMZ0170 4510449 Murata

Crystal (B601) TSX-8A-25850 4510337 Toyocom

Tx Coupler (L801) LDC21836M19D-185 4550197 Murata

Tx850 buffer (V802) BFR949T-E6327 4210171 Infineon

RF test points

The RF power supplies are generated in the UEM and can be measured either in the Mjoelner chamber or in the base band chamber. On the drawing below small circles show the locations of the test points.

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Test points RF supply voltages

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RF test points Mjoelner chamber

RF test points VCO chamber

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RF test points PA chamber

Test points BB area

J203 TXQD

J201 RXQD

J202 TXID

J200 RXID

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Receiver Troubleshooting

General instructions for RX troubleshooting

Connect the phone to a PC with Phoenix dongle PKD-1CS and DAU-9S cable (RS232). Follow the instructions below.

Connect the phone to a power supply (DC voltage of 3.6V) and an RF signal generator.

Measuring RX I/Q signals using RSSI reading

1 Start Phoenix Service Software and open FBUS connection:

Select Scan Product Ctrl-R

Wait until phone information is shown in the lower right corner of the screen.

2 Set operating mode to local mode:

Select Maintenance Alt-M

Testing T

RF Controls F

Wait until the RF Controls window pops up.

3 In the RF Controls window:

Select Band GSM850 or GSM1900

Active unit RX Operation mode Burst RX/TX Channel 190 or 661

Select Maintenance Alt-M

Testing T RSSI reading R

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The setup should now look like this:

4 Make the following settings on your signal generator:

Frequencies:

GSM850: 881.66771 MHz (channel 190 + 67.710kHz offset)

GSM1900: 1960.06771 MHz(channel 661 + 67.710kHz offset)

RF power level:

– 80dBm @ the antenna connector of the phone (remembering to compensate for the cable and jig attenuation).

5 In RSSI reading, click Read now.

The resulting RSSI level should be – 80dBm +/– 0.5dB in each band.

Measuring RX performance using SNR measurement

1 Start Phoenix Service Software and open FBUS connection.

Select Scan Product Ctrl-R

Wait until phone information is shown in the lower right corner of the screen.

2 Set operating mode to local mode.

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Select Maintenance Alt-M

Testing T

RF Controls F

Wait until the RF Controls window pops up.

3 In the RF Controls window:

Select Band GSM850 or GSM1900

Active unit RX Operation mode Burst RX/TX Channel 190 or 661

Select Maintenance Alt-M

Testing T

SNR Measurement M

Select Both (Radio Button)

The setup should now look like this:

4 Press the Start button.

5 To continue, follow the instructions in the following pop-up windows.

6 Connect an external signal generator to the RF connector of the phone and set

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the generator as instructed in the window. Take care for external cable and test jig attenuation losses.

7 Switch off the external RF signal as instructed in the next pop-up window.

8 Press OK and read the SNR result.

The values should be:

GSM850 > 20dB GSM1900 > 18dB

Measuring front-end power levels using spectrum analyzer

Spectrum Analyzer (SA) level values depend on the probe type and should be validated using a good sample. The levels that are given here are measured using an hp 85024A probe.

1 Start Phoenix Service Software and open FBUS connection:

Select Scan Product Ctrl-R

Wait until phone information is shown in the lower right corner of the screen.

2 Set operating mode to local mode:

Select Maintenance Alt-M

Testing T

RF Controls F

Wait until the RF Controls window pops up

3 In the RF Controls window:

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Select Band GSM850 or GSM1900

Active unit RX Operation mode Continuous RX/TX Channel 190 or 661

Please refer to the fault-finding chart and Appendix C for proper levels at different test points.

Measuring analogue RX I/Q signals using oscilloscope

Measuring with an oscilloscope on “RXIINN” or “RXQINN” is recommended only if RSSI reading does not provide enough information. There are dedicated test points for RX I and Q signals. Apply an Input signal level of -80dBm.

1 Start Phoenix Service Software and open FBUS connection:

Select Scan Product Ctrl-R

Wait until phone information is shown in the lower right corner of the screen.

2 Set operating mode to local mode:

Select Maintenance Alt-M

Testing T

RF Controls F

Wait until the RF Controls window is pops up.

3 In the RF Controls window:

Select Band GSM850 or GSM1900

Active unit RX Operation mode Continuous RX/TX Channel 190 or 661 AGC 14

Following picture should be displayed on an oscilloscope' s screen if the GSM850

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receiver is working properly:

Receiver troubleshooting

The phone layout has dedicated test points for the analogue differential RX I and Q signals (RXIINP, RXIINN, RXQINP, RXQINN) from Mjoelner RF ASIC to UEM. The BB part is used to measure those signals by means of RSSI reading. It is assumed that correct calibration of RSSI reading has been carried out in production.

RSSIreading [dBm] = 20log(U

Therefore, do not calibrate a defective phone before the phone error has been found.

When a defective phone has been calibrated, a possible error in RX front-end might be masked. In that case one can get a reasonable RSSI reading, although the front-end shows excessive losses.

If you are not sure that incorrect re-calibration has been made, the following steps should be done:

1 Check if AGC calibration is within limits.

) + AGC

calibrated

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2 Check if SNR reading is OK.

Use an Oscilloscope to check levels of “RXIINN” and “RXQINN”.

Make sure that Synthesiser is working

Note: RF levels given in that chart are dependent on RF probe and m ust be v alidated with a known good sample

Apply -80dBm signal from Generator to Antenna Connector phone: local, burst mode

GSM, PCS

RSSI reading

-80dBm

all bands

RX calibration

Calibration.

Rx chain functional

= to be done in all 3 bands

within limits

GSM, PCS

Apply -92dBm signal

Yes

from Generator to Antenna Connector phone: local, burst mode

SNR measurement

all bands

o.k.

Yes

= to be done in defective band only

= to be done only once (common for all bands)

wrong in both

Change signal level to -60dBm phone: local, continous mode

Check RxTx Switch

RSSI

and SN R

bands

Z601

Rx output EGSMout

(850 &1900)

-76dBm

> -67dBm

Change

Z601

Yes

Check SAW

Osci:

RF-BB

Z601

serial

EGSMout Interface

-76dBm o.k.

BB Error

Check UPP

SA SA

Z604,Z603

Z601

SAWout EGSMout

both lines

-76dBm

>-72dBm

Change

Z604, Z603

Yes

EGSMout

Change

Mjolner

Check Bias

C620, C632

Osci:

RX I/Q

Z601

level

o.k.

-76dBm ?

Osci:

LNA bias

Z601

(VR4)

EGSMout

=2.8V

-76dBm ?

Check

and

BB (UEM)

Yes

BB Error

Check UEM

Check Bias

RX -BB bias

Yes

EGSMout

BB (UEM)

If RX and TX path seem to be faulty it has to be checked if the synthesizer is working. If yes, then check the path from the antenna test pad J800 to the antenna switch Z601 (see RX troubleshooting "Check RXTX switch").

Osci:

Z601 (VR4) =2.8V

-76dBm

Check

C871

and

Check

Yes

LNA

Yes

Osci:

LNA

Z601

base voltage

EGSMout

= 0.8V

-76dBm ?

Change

Mjoelner

Rx signal paths

The signal paths of the receiver are shown in following block diagram. Note that the diagram shows GSM850 receiver (above) and the GSM1900 receiver (below).

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Nokia N-GageQDa Service Manual 07 rh47 RF.book

Table of Contents

Abbreviations

Introduction to RF

RF power supply configuration

General specifications of transceiver RH-47

Introduction to RF Troubleshooting

Printed Wired Board

RF key component placement

RF test points

Test points RF supply voltages

RF test points Mjoelner chamber

RF test points VCO chamber

RF test points PA chamber

Test points BB area

Receiver Troubleshooting

General instructions for RX troubleshooting

Measuring RX I/Q signals using RSSI reading

Measuring RX performance using SNR measurement

Measuring front-end power levels using spectrum analyzer

Measuring analogue RX I/Q signals using oscilloscope

Receiver troubleshooting

Rx signal paths