Customer Care Solutions
RM-37 Series Transceivers
6-Troubleshooting Instructions
Issue 1 04/2004 ©Nokia Corporation
RM-37 Company confidential
6-Troubleshooting Instructions CCS Technical Document ation
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Page 2 ©Nokia Corporation. Issue 1 04/2004
Company confidential RM-37
CCS Technical Documentation 6-Troubleshooting Instructions
Table of Contents
Page No
RF Troubleshooting .......................................................................................................4
Introduction to RF troubleshooting .............................................................................4
RF Key component placement .....................................................................................5
RF Measurement points ...............................................................................................6
GSM900 & GSM1800 Transmitter ................................................................................7
General instructions for Tx troubleshooting .............................................................7
Transmitter troubleshooting diagram ........................................................................9
Pictures of transmitter signals .................................................................................12
GSM900, GSM1800 and GSM1900 Receiver .............................................................14
General instructions for Rx troubleshooting ...........................................................14
Troubleshooting diagram for GSM900 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
Main Troubleshooting Diagram ................................................................................25
Phone is dead .............................................................................................................26
Flash Programming Fault ..........................................................................................27
Phone is jammed ........................................................................................................28
SIM card fault (Insert SIM / Card rejected) ...............................................................29
Keypad Fault ..............................................................................................................30
Display Fault ..............................................................................................................32
Illumination fault .......................................................................................................33
Charger Fault .............................................................................................................34
Accessory Fault .........................................................................................................35
Camera Troubleshooting ..............................................................................................36
Camera Fault ..............................................................................................................37
Audio Fault ................................................................................................................38
FM Radio troubleshooting ...........................................................................................39
FM Radio component layout .....................................................................................39
FM Radio troubleshooting diagram ...........................................................................41
Notes to "FM Radio troubleshooting diagram" .......................................................41
Issue 1 04/2004 ©Nokia Corporation. Page 3
RM-37 Company confidential
6-Troubleshooting Instructions CCS Technical Document ation
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 build 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 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 duriong 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 6-Troubleshooting Instructions
RF Key component placement
Figure 1: Component placement 1
GSM 1900
rx saw
Antenna
switch
GSM 1900
rx balun
VCTCXO
PA
GSM900tx
Balanced saw
Helga
VCO
VCO balun
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RM-37 Company confidential
6-Troubleshooting Instructions CCS Technical Document ation
RF Measurement points
Figure 2: Component placement 2
VBATT
RX-saw-out
LNA-P
to antenna
ASM-out-1900RX
LNA-VCC
VANT-3
RFBusEn
RFBusClk
RFBusRes
RFBusData
VCTCXO 26MHz out
VR2
VR3
VR1
VANT-2
VANT-1
ASM-in
1800-1900PA-in
VTXB-1800-1900
PCRTL-1800-1900
VPCTRL-900
VTXB-900
900PA-in
1800RX-in
1900RX-in
900RX-in
VR7
VR6
VR4
TXC
VR5
TXQP
TXIN
TXIP
TXQN
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Company confidential RM-37
CCS Technical Documentation 6-Troubleshooting Instructions
GSM900 & 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-38) 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 -> RM-37
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 "GSM900" or "GSM 1800" or "GSM1900" (Default = "GSM900")
- Set Active unit to "Tx" (Default = "Rx")
- Set Operation mode to "Burst" (Default = "Burst")
- Set Tx data type to "Random" (Default = "All1")
Issue 1 04/2004 ©Nokia Corporation. Page 7
RM-37 Company confidential
6-Troubleshooting Instructions CCS Technical Document ation
- Set Rx/Tx channel to 37 on GSM900 band or 700 on GSM1800 band or 661 on
GSM1900 (Defaults)
- Set Tx PA mode to "Free" (Default)
- Set power level to 5 (Default = 19) on GSM900 or to 0 (Default = 15) on GSM1800 or
GSM1900
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Transmitter troubleshooting diagram
CCS Technical Documentation 6-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)
OK ?
TX signal found ?
Yes
Check with RF probe
signal level on
PA input >=0dBm (*
OK ?
Yes
start TX power level
tuning and check
tuned RAC values:
Highest level~700...900
Lowest level ~190...210
Base levle ~160...190
Major differences ?
No
TX OK
Yes
Yes
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
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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RM-37 Company confidential
6-Troubleshooting Instructions CCS Technical Document ation
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 ?
No
Baseband
troubleshooting
Check with RF probe:
-4G VCO out signal
- 3589.6 MHz (GSM900)
-3495.6 MHz (GSM1800)
- 3760 MHz (GSM1900)
Level >-10dBm (*
OK ?
Check modulator
output components
OK ?
Replace
faulty
component(s)
No
*(When 1kOhm passive probe is used,
correct the measurement result by +26dB
Yes
Synthesizer
troubleshooting
Replace HELGA
dead
Page 10 ©Nokia Corporation. Issue 1 04/2004
Company confidential RM-37
CCS Technical Documentation 6-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)
OK ?
Yes
No
Replace
PA
Check components
around PA
OK ?
Yes
Yes
Check with
oscilloscope:
-VANT_1 (GSM900)
-VANT_2 (GSM1800)
-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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RM-37 Company confidential
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v
6-Troubleshooting Instructions CCS Technical Documentation
Pictures of transmitter signals
Figure 6: Transmitter signals
TXI
VPC
200mV/di
1
VPCTRL _900 power level high at R703/C703
VPCTRL_1800/1900 power level high at R704/C704
500mV/div 100us/div
VANT_1 / GSM900 TX at C804
VANT_2 / GSM1800 TX at R808
VANT_3 / GSM1900 TX at C805 OV
( no signal/ Flatline on Oscilloscope screen)
100us/di
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
VTXB_900 at C713
VTXB_1800_1900 at C714
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500mV/div 100us/div
500mV/div MTB 100us/div
TXP at J504
Company confidential RM-37
CCS Technical Documentation 6-Troubleshooting Instructions
Figure 7: TX OUT signal
GS MPOW Tue Sep 25 13: 48 : 59 2001
REF 41. 0 dBm ATT 40 dB
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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RM-37 Company confidential
6-Troubleshooting Instructions CCS Technical Documentation
GSM900, 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-38) 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 -> RM-37
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 "GSM900", "GSM 1800" or “GSM1900” (Default = "GSM900")
- 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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