Nokia 5100 Service Manual 06 npm6_6x trouble

CCS Technical Documentation

NPM-6/6X Series Transceivers

Troubleshooting Instructions

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Troubleshooting Instructions CCS Technical Documentation

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CCS Technical Documentation Troubleshooting Instructions

Table of Contents

Page No

RF Troubleshooting ....................................................................................................... 4

Introduction to RF troubleshooting .............................................................................4

RF Key component placement .....................................................................................5

RF Measurement points ...............................................................................................6

EGSM900 & GSM1800 Transmitter ............................................................................. 7

General instructions for Tx troubleshooting ............................................................. 7

Transmitter troubleshooting diagram ........................................................................ 9

Pictures of transmitter signals ................................................................................. 12

EGSM900, GSM1800 and GSM1900 Receiver .......................................................... 14

General instructions for Rx troubleshooting ........................................................... 14

Troubleshooting diagram for EGSM900 receiver................................................... 18

Troubleshooting diagram for GSM1800 receiver ................................................... 19

Troubleshooting diagram for GSM1900 receiver ................................................... 20

Synthesizer ................................................................................................................... 21

General instructions for synthesizer troubleshooting.............................................. 21

Synthesizer troubleshooting diagram ...................................................................... 22

Pictures of synthesizer signals................................................................................. 23

Baseband Troubleshooting........................................................................................... 25

BB Measurement points ............................................................................................25

Troubleshooting diagrams .........................................................................................27

FM Radio troubleshooting ........................................................................................... 48

FM Radio component layout .....................................................................................48

FM Radio troubleshooting diagram ...........................................................................50

Notes to "FM Radio troubleshooting diagram"....................................................... 50

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RF Troubleshooting

Introduction to RF troubleshooting

Measurements should be done using Spectrum analyzer with high-frequency highimpedance passive probe (LO-/reference frequencies and RF power levels) and Oscilloscope with a 10:1 probe (DC-voltages and low frequency signals)

The RF-section is built around one RF-ASIC (HELGA N500). For easier troubleshooting, this RF troubleshooting document is divided in to sections.

Before changing HELGA, please check following things: Supply voltages are OK and serial communication is coming from baseband to HELGA.

Please note that the grounding of the PA module is directly below PA-module so it is difficult to check or change. Most RF semiconductors are static discharge sensitive! So ESD protection must be taken care of during repair (ground straps and ESD soldering irons). HELGA and PA are moisture sensitive so parts must be pre-baked prior to soldering.

Apart from key components described in this document here are a lot of discrete components (resistors, inductors and capacitors) which troubleshooting is done by checking if soldering of the component is done properly (for factory repairs checking if it is missing from PWB). Capacitor can be checked for shortening and resistors for value by means of an ohmmeter, but be aware in-circuit measurements should be evaluated carefully.

Please be aware that all measured voltages or RF levels in this document are rough figures. Especially RF levels varies due to different measuring equipment or different grounding of the used probe. When using RF probe usually a good way is to use metallic tweezers to connect probe ground to PWB ground as close to measurement point as possible.

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RF Key component placement

Figure 1: Component placement 1

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RF Measurement points

Figure 2: Component placement 2

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EGSM900 & GSM1800 Transmitter

General instructions for Tx troubleshooting

Kindly refer to the Service Software Section, Service Concept dagram (p.40)

Connect test jig to computer with DAU-9S cable or to FPS-8 Flash Prommer with XCS-4 modular cable.

Make sure that you have PKD-1 dongle connected to computers parallel port.

Connect DC power supply to module test jig with FLC-2 cable.

Attention: When repairing or tuning transmitter use external DC supply with at least 3A current capability. Set the DC supply voltage to 3.9V and set the jumper con-

nector on test jig to "bypass" position.

Connect a RF-cable to the module test jig (MJS-49) RF connector to and to measurement equipment or at least 10dB attenuator, otherfwise the PA may be damaged. Normally Spectrum analyzer is used as measurement equipment.

Attention: Normally Spectrum analyzer maximum input power is +30dBm. It is recommended to use 10dB attenuator on Spectrum analyzer input to prevent damage.

Set the phone module to test jig and start Phoenix service sofware

Initialize connection to phone. (use FBUS driver when using DAU9S and COMBOX driver when using FPS-8)

Select product from the menu

File -> Choose product -> NPM-6

From toolbar set operating mode to "Local"

Activate RF controls window from the menu

Maintenance -> Testing -> RF Controls

From the RF controls window

- Select band "EGSM900" or "GSM 1800" or "GSM1900" (Default = "EGSM900")

- Set Active unit to "Tx" (Default = "Rx")

- Set Operation mode to "Burst" (Default = "Burst")

- Set Tx data type to "Random" (Default = "All1")

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- Set Rx/Tx channel to 37 on EGSM900 band or 700 on GSM1800 band or 661 on EGSM1900 (Defaults)

- Set Tx PA mode to "Free" (Default)

- Set power level to 5 (Default = 19) on EGSM900 or to 0 (Default = 15) on GSM1800 or GSM1900

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(EGSM900

CCS Technical Documentation Troubleshooting Instructions

Transmitter troubleshooting diagram

Figure 3: Transmitter troubleshooting

TX troubleshooting

Check output signal level: +32...+33dBm @897.4 MHz (GSM900) +29...+30dBm @1747.8 MHz (GSM1800 & GSM1900)

Check with RF probe signal level on PA input >=0dBm (*

start TX power level tuning and check tuned RAC values: Highest level~700...900 Lowest level ~190...210 Base levle ~160...190

Major differences ?

OK ?

TX signal found ?

Yes

OK ?

Yes

Check output signal on 500 MHZ span Signal found on incorrect frequency ?

*(When 1kOhm passive probe is used, correct the measurement result by +26dB

Yes

TX OK

Yes

Check all power levels, OK ?

HELGA troubleshooting

Tune Tx DAC values

Yes

Tune TX power levels, OK ?

Synthesizer troubleshooting

Check with oscilloscope: PA ctrl voltage >1.5V peak OK ?

Yes

PA & ant switch

troubleshooting

Check control loop components

Yes

Replace faulty component(s)

OK ?

Yes

Replace HELGA

dead

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Figure 4: HELGA IC troubleshooting

HELGA troubleshooting

Check with oscilloscope:

-TXI/TXQ signals

--VR1, VR2, VR4, VR5, VR6 = 2.8V

-VrefRF01 = 1.35 V

-HELGA serial interface

-TXP & TXC signals OK ?

Baseband troubleshooting

Check with RF probe:

-4GVCO out signal

-4G VCO out signal

- 3589.6 MHz (GSM900)

-3589.6MHz (EGSM900)

-3495.6 MHz (GSM1800)

- 3760 MHz (GSM1900)

-3760 MHz (GSM1900)

Level >-10dBm (*

Level >-10dBm

OK ?

Check modulator output components

OK ?

Replace faulty component(s)

Synthesizer troubleshooting

*(When 1kOhm passive probe is used, correct the measurement result by +26dB

Yes

Replace HELGA

dead

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Figure 5: PA and Antenna Switch troubleshooting

PA & ant switch

troubleshooting

*(When 1kOhm passive probe is used,

Yes

correct the measurement by +26dB

Check with RF probe signal level on PA input >=0dBm (*

OK ?

Yes

Check with oscilloscope:

-VBATT ~4V

- VTXB = 2.8 V pulsed

- VTxLO_GSM = 0V (GSM900)

(EGSM900)

OK ?

Yes

Replace PA

Check components around PA

OK ?

Yes

Check with oscilloscope:

-VANT_1 (GSM900)

-VANT_1 (EGSM900)

-VANT_2 (GSM1800)

-VANT_3 (GSM1900)

OK ?

Check VANT lline components

OK ?

Yes

Replace HELGA

Replace ant. switch

Replace faulty component(s)

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Pictures of transmitter signals

Figure 6: Transmitter signals

TXI

VPC

200mV/div

VPCTRL _900 power level high at R703/C703 VPCTRL_1800/1900 power level high at R704/C704

500mV/div 100us/div

VANT_1 / EGSM900 TX at C804 VANT_2 / GSM1800 TX at C835

100us/di

VANT_3 / GSM1900 TX at C805 OV ( no signal/ Flatline on Oscilloscope screen)

200mV/div

100us/div

TX I/Q at R516/517 power level high Random data

500mV/div 100us/div

VANT_1,VANT_2,VANT_3

500mV/div MTB 100us/div

VTXB_900 at C713 VTXB_1800_1900 at C714

500mV/div 100us/div

TXP at J504

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Figure 7: TX OUT signal

GS MPOW Tue Sep 25 13: 48: 59 2001 REF 4 1. 0 d Bm ATT 4 0 d B 10dB/

REF OFS

11. 0 dB

RBW

100 kHz

VBW

100 kHz

SWP

2. 0 s CENTER 897. 400 MHz SPAN 2. 000 MHz

Tx out signal, 900 band, burst mode, channel 37

A_wr i t eB_bl ank

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EGSM900, GSM1800 and GSM1900 Receiver

General instructions for Rx troubleshooting

Connect test jig to computer with DAU-9S cable or to FPS-8 Flash Prommer with XCS-4 modular cable.

Make sure that you have PKD-1 dongle connected to computers parallel port.

Connect DC power supply to module test jig with FLC-2 cable.

Set the DC supply voltage to 6V (test jig has internal voltage regulator of output voltage 4V).

Connect an RF-cable to the module test jig (MJS-49) RF connector and to RF signal generator.

Set the phone module to test jig and start Phoenix service sofware.

Initialize connection to phone. (use FBUS driver when using DAU9S and COMBOX driver when using FPS-8)

Choose product from the menu

File -> Choose product -> NPM-6

From toolbar set operating mode to "Local"

Activate RF controls window from the menu

Maintenance -> Testing -> RF Controls

From the RF controls window:

- Select band "EGSM900", "GSM 1800" or “GSM1900” (Default = "EGSM900")

- Set Active unit to "Rx" (Default = "Rx")

- Set Operation mode to "Burst" (Default = "Burst")

For continuous mode:

- Set Operation mode to "Continuous"

- Set AGC to "12: FEG_ON + DTOS_ON + BB_30=Vgain60” (maximum gain setting used in normal mode)

(Default = "14: FEG_ON + DTOS_ON + BB_42=Vgain72")

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- Set Rx/Tx channel to 37 on EGSM900 band, 700 on GSM1800 band or 661 on GSM1900 (Defaults)

Apply 942.46771 MHz (channel 37 + 67.710 kHz offset), 1842.86771 MHz (channel 700 + 67.710 kHz offset) or 1960.06771 MHz (channel 661 + 67.71 kHz) –90 dBm signal to the RF-connector (remember to compensate for cable attenuation).

Measuring with an oscilloscope on "RXI" or "RXQ" following screens should be seen on a working EGSM900 , GSM1800 or GSM1900 receiver:

Figure 8: RX I/Q signal ,burst mode, input level –90dBm.

Figure 8, “RX I/Q signal ,burst mode, input level –90dBm.,” on page 15: Receiver I or Q burst mode signal (channel 37) measured from testpoint RXI or RXQ with 942.467 MHz signal, input level –90dBm at RF-connector.

Correct signal amplitudes approximately:

• EGSM900~170mVpp

• GSM1800~140mVpp

• GSM1900~160mVpp

Signal part frequency 67.7kHz sine.

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DC level of signal part is 1.35V. DC level can variate about +/-100mV between I and Q signals and between different bands as well.

Figure 9: GSM1900 RX I or Q signal (trace2), burst mode.

For GSM1900 receiver burst mode I or Q signal at ch 661 with input signal

1960.067MHz, level –90 dBm at RF-connector.

Trace2: With wider time scaling both monitoring and own RX bursts are seen, 1st burst (shorter) is monitoring and 2nd burst (longer) is own RX burst.

Trace1: External LNA VCC supply voltage at burst mode, input level –90 dBm. Measured from testpoint LNA_VCC.

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Figure 10: RX I&Q, phase difference 90 deg between signals.

Figure 10, “RX I&Q, phase difference 90 deg between signals.,” on page 17:

Detailed view of EGSM900 continuous mode RX I and Q signals measured from testpoints RXI and RXQ simultaneously.

Used channel 37, input signal 942.467 MHz, level –90 dBm at antenna port, AGC setting

12.

Phase difference should be 90 degrees between RX I and Q signals at all bands.

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