Nokia 5100 Service Manual 08_npm6_trouble

NPM-6 Series Transceiver

Troubleshooting Instructions

Issue 1 01/03 ãNokia Corporation

Troubleshooting Instructions CCS Technical Documentation

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Page 2 ãNokia Corporation. Issue 1 01/03

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

FM Radio troubleshooting ...........................................................................................46

FM Radio component layout .....................................................................................46

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

Notes to "FM Radio troubleshooting diagram" .......................................................48

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Troubleshooting Instructions CCS Technical Documentation

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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CCS Technical Documentation Troubleshooting Instructions

RF Key component placement

Figure 1: Component placement 1

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Troubleshooting Instructions CCS Technical Documentation

RF Measurement points

Figure 2: Component placement 2

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CCS Technical Documentation Troubleshooting Instructions

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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Troubleshooting Instructions CCS Technical Documentation

- 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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CCS Technical Documentation Troubleshooting Instructions

(EGSM900

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

No

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

No

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

Yes

TX OK

Yes

Yes

Check
all power
levels,
OK ?

No

HELGA
troubleshooting

Tune Tx DAC values

No

Yes

Tune
TX power
levels,
OK ?

Synthesizer
troubleshooting

No

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

Yes

PA & ant switch

troubleshooting

Check control loop
components

No

Yes

Replace
faulty
component(s)

OK ?

Yes

Replace HELGA

dead

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Troubleshooting Instructions CCS Technical Documentation

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 ?

Check with RF probe:

Check with RF probe:

-4GVCO out signal

-4G VCO out signal

- 3589.6 MHz (GSM900)

-3589.6MHz (EGSM900)

-3495.6 MHz (GSM1800)

-3495.6 MHz (GSM1800)

- 3760 MHz (GSM1900)

-3760 MHz (GSM1900)

Level >-10dBm (*

Lvl >-1

Bm

OK ?

No

Baseband
troubleshooting

No

Synthesizer
troubleshooting

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

Check modulator
output components

OK ?

Replace
faulty
component(s)

Yes

Replace HELGA

dead

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CCS Technical Documentation Troubleshooting Instructions

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

No

Replace
PA

Check components
around PA

OK ?

Yes

Yes

Check with
oscilloscope:

-VANT_1 (GSM900)

-VANT_1 (EGSM900)

-VANT_2 (GSM1800)

-VANT_2 (GSM1800)

-VANT_3 (GSM1900)

-VANT_3 (GSM1900)

OK ?

No

Check
VANT lline components

OK ?

Yes

Replace
HELGA

Replace
ant. switch

No

Replace
faulty
component(s)

No

Replace
faulty
component(s)

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Troubleshooting Instructions CCS Technical Documentation

Pictures of transmitter signals

Figure 6: Transmitter signals

TXI

VPC

200mV/div

1

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

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

100us/div

200mV/div

100us/div

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

_

1
500mV/div 100us/div

VANT_1,VANT_2,VANT_3

500mV/div 100us/div

VTXB_900 at C713
VTXB_1800_1900 at C714

500mV/div MTB 100us/div

TXP at J504

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CCS Technical Documentation Troubleshooting Instructions

Figure 7: TX OUT signal

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

REF OF S

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_b l ank

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Troubleshooting Instructions CCS Technical Documentation

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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CCS Technical Documentation Troubleshooting Instructions

- 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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Troubleshooting Instructions CCS Technical Documentation

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.

st

Trace2: With wider time scaling both monitoring and own RX bursts are seen, 1

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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