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
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
Troubleshooting Instructions CCS Technical Documentation
RF Measurement points
Figure 2: Component placement 2
Page 6 ãNokia Corporation. Issue 1 01/03
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")
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
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)
Issue 1 01/03 ãNokia Corporation. Page 11
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
Page 12 ãNokia Corporation. Issue 1 01/03
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
Issue 1 01/03 ãNokia Corporation. Page 13
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.
Issue 1 01/03 ãNokia Corporation. Page 15
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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