Page 1
Nokia Customer Care RH-37 Series Transceivers 6(b) - RF Troubleshooting Instructions 2004 Nokia Corporation Issue 1 07/04 Page 1 Company Confidential...
Page 2
RH-37 6(b) - RF Troubleshooting Instructions Nokia Customer Care [This page left intentionally blank] Nokia Corporation Page 2 Issue 1 07/04...
RH-37 Nokia Customer Care 6(b) - RF Troubleshooting Instructions Table of Contents Page No General Information on RF Troubleshooting..................5 Test environment ..........................5 Test conditions ............................6 Receiver Verification and Troubleshooting ..................7 General instructions for RX troubleshooting ................7 Measuring RX I/Q signals using RSSI reading ................
Page 4
RH-37 6(b) - RF Troubleshooting Instructions Nokia Customer Care [This page left intentionally blank] Nokia Corporation Page 2 Issue 1 07/04...
RH-37 Nokia Customer Care 6(b) - RF Troubleshooting Instructions General Information on RF Troubleshooting Notes: Several bills of material (BOM): There are two different kinds of VCOs, VCTXOs, RF-PAs, SAW-fil- ters and Antenna Switches (ASM) assembled. They may only be replaced with the same type as the original component (from the same manufacturer).
RH-37 6(b) - RF Troubleshooting Instructions Nokia Customer Care Test conditions Rx tuning of the 26 MHz reference oscillator (VCTCXO) is temperature sensitive because of the estimations of <AFC_value> and <AFC_slope>. According to the Produc- tion Test Specification DCS02294-EN-0.5, the ambient temperature has to be within a temperature range of 22°C to 28°C.
RH-37 Nokia Customer Care 6(b) - RF Troubleshooting Instructions Receiver Verification and Troubleshooting General instructions for RX troubleshooting Connect the phone to a PC, which has Phoenix Service Software and a dongle installed, using either • repair jig and DAU-9S (RS232) cable or •...
Page 8
RH-37 6(b) - RF Troubleshooting Instructions Nokia Customer Care RSSI reading In the RSSI Reading window, the <measuring mode> shall be set on Sum vector and the <reading mode> on Continuous. The set up should now look like this: (The example below shows a screen shot in GSM900!)
RH-37 Nokia Customer Care 6(b) - RF Troubleshooting Instructions Measuring RX performance using SNR measurement Start Phoenix Service Software and open FBUS connection. Select Scan Product Ctrl-R Wait until the phone information is shown in the lower right corner of the screen.
RH-37 6(b) - RF Troubleshooting Instructions Nokia Customer Care (The example below shows a screen shot in GSM900!) Choose the remaining GSM bands and measure accordingly the procedure described above. Measuring front-end power levels using spectrum analyzer Spectrum analyzer (SA) level values depend on the probe type and shall be verified by a properly working phone sample.
RH-37 Nokia Customer Care 6(b) - RF Troubleshooting Instructions RX/TX Channel 37 or 700 or 661 Please refer to the fault finding chart and Appendix for proper levels at different test points. Measuring analogue RX I/Q signals using oscilloscope Measuring with an oscilloscope RX I and RX Q signals on the test points <RXI> respec- tively <RXQ>...
RH-37 6(b) - RF Troubleshooting Instructions Nokia Customer Care Signal amplitude 1.40Vpp ≈ 1.28V as the offset is floating, switch to the operating mode DC offset <Burst> in Phoenix and read the DC offset Frequency 67kHz Fault finding chart of the receiver...
Page 13
RH-37 Nokia Customer Care 6(b) - RF Troubleshooting Instructions VrefRF02. The phone layout has dedicated test points for the analogue RX I and Q signals (J512, J513). The BB part is used to measure those signals by means of RSSI reading. This works only if correct calibration has been carried out in production.
Page 14
RH-37 6(b) - RF Troubleshooting Instructions Nokia Customer Care Receiver Make sure that Fault Finding Tree Synthesizer Fault Synthesizer is working part 1 Finding Tree = To be done in all three bands. All 3 bands Phoenix: Phone: local mode...
Page 15
RH-37 Nokia Customer Care 6(b) - RF Troubleshooting Instructions Oscilloscope : Check supply filter Receiver Check reference voltages of RF part: components (R7511, Fault Finding Tree VrefRF01 = 1.35V ? C7524) and UEM part 4 (TP: VrefRF01*) Oscilloscope : Check supply filter...
Page 16
RH-37 6(b) - RF Troubleshooting Instructions Nokia Customer Care Single band fault finding Select faulty band in Phoenix and continue measurements on dedicated Rx part. Receiver Fault Finding Tree Phoenix: open SNR Measurement part 7 Meas. Mode: Fast SNR Press Measure .
Page 17
RH-37 Nokia Customer Care 6(b) - RF Troubleshooting Instructions Receiver Fault Finding Tree If selected band = GSM1900 part 9 Spectrum Analyzer: Check SAW filter Z7801: Change Z7801 TP: OUT-Z7801 Output signal > Pref - 3.5dB Oscilloscope: Check supply Spectrum Analyzer:...
Page 18
RH-37 6(b) - RF Troubleshooting Instructions Nokia Customer Care Channel select filter fault finding Continue measurement only when channel select filter calibration failed Receiver Fault Finding Tree Make sure that Synthesizer is part 10 working and supply voltages of RF ASIC are ok...
RH-37 Nokia Customer Care 6(b) - RF Troubleshooting Instructions Transmitter General instructions for TX troubleshooting Connect the phone to a PC, which has Phoenix Service Software and a dongle installed, using either • repair jig and DAU-9S (RS232) cable or •...
Page 20
RH-37 6(b) - RF Troubleshooting Instructions Nokia Customer Care GMSK Set operating mode to local mode. Select Testing RF Controls Wait until the RF Controls window pops up Select Band GSM 900 Active unit Operation mode Burst RX/TX Channel TX Power Level...
Page 21
RH-37 Nokia Customer Care 6(b) - RF Troubleshooting Instructions = +23dBm @ 897.4 MHz If this is not the case, go to the GMSK fault finding chart for the GSM900 transmitter. EDGE Set operating mode to local mode. Select Testing RF Controls Wait until the RF Controls window pops up.
RH-37 6(b) - RF Troubleshooting Instructions Nokia Customer Care Now the measurement equipment should detect the following output signal of the phone: = +24.5 dBm @ 897.4 MHz If this is not the case, go to the EDGE fault finding chart for GSM900 transmitter.
Page 23
RH-37 Nokia Customer Care 6(b) - RF Troubleshooting Instructions GMSK Use Phoenix to select TX_Data Type: Random TX Power Level: 10 Ch37 Ensure Vbatt=3.6 V Oscilloscope C7711 Mode V = 0 Volt R7511 VREF01 Vdc = 1.35 Volt Check C7512 Vdc = 2.78 Volt...
RH-37 6(b) - RF Troubleshooting Instructions Nokia Customer Care EDGE Ensure that GMSK is ok. Use Phoenix to select TX_Data Type: All 1 EDGE: On TX Power Level: 10 Ch37 Ensure Vbatt=3.6 V Oscilloscope IREF01 C7702 V ~ 1.77 Volt...
Page 25
RH-37 Nokia Customer Care 6(b) - RF Troubleshooting Instructions The setup should now look like this: Now the measurement equipment should detect the following output signal of the phone: = +23dBm @ 1747.8 MHz If this is not the case, then go to the GMSK fault finding chart for GSM1800 transmitter.
RH-37 6(b) - RF Troubleshooting Instructions Nokia Customer Care TX Data Type All 1 Edge The setup should now look like this: Now the measurement equipment should detect the following output signal of the phone: = +21.5 dBm @ 1747.8 MHz If this is not the case, then go to the EDGE fault finding chart for GSM1800 transmitter.
Page 27
RH-37 Nokia Customer Care 6(b) - RF Troubleshooting Instructions GMSK TX_Data Type: Random TX Power Level: 5 Ch700 Ensure Vbatt=3.6 V Oscilloscope C7711 Mode V = 0 Volt VREF01 R7511 Vdc = 1.35 Volt Check C7512 Vdc = 2.78 Volt...
RH-37 6(b) - RF Troubleshooting Instructions Nokia Customer Care EDGE Ensure that GMSK is ok. Use Phoenix to select TX_Data Type: All 1 EDGE: On TX Power Level: 5 Ch700 Ensure Vbatt=3.6 V Oscilloscope IREF_900 C7702 V = 1.83 Volt...
Page 29
RH-37 Nokia Customer Care 6(b) - RF Troubleshooting Instructions The setup should now look like this: Now the measurement equipment should detect the following output signal of the phone: = +23dBm @ 1880 MHz If this is not the case, then go to the GMSK fault finding chart for GSM1900 transmitter.
RH-37 6(b) - RF Troubleshooting Instructions Nokia Customer Care Edge The setup should now look like this: Now the measurement equipment should detect the following output signal of the phone: = +21.5 dBm @ 1880 MHz If this is not the case, then go to the EDGE fault finding chart for GSM1900 transmitter.
Page 31
RH-37 Nokia Customer Care 6(b) - RF Troubleshooting Instructions GMSK Use Phoenix to select TX_Data Type: Random TX Power Level: 5 Ch661 Ensure Vbatt=3.6 V Oscilloscope C7711 Mode Vdc = 0 Volt VREF01 R7511 Vdc = 1.35 Volt Check C7512 Vdc = 2.78 Volt...
Page 32
RH-37 6(b) - RF Troubleshooting Instructions Nokia Customer Care EDGE Ensure that GMSK is ok. Use Phoenix to select TX_Data Type: All 1 EDGE: On TX Power Level: 5 Ch661 Ensure Vbatt=3.6 V Oscilloscope IREF_900 C7702 V = 1.83 Volt...
RH-37 Nokia Customer Care 6(b) - RF Troubleshooting Instructions Synthesizer General instructions for synthesizer troubleshooting Connect the phone to a PC, which has Phoenix Service Software and a dongle installed, using either • repair jig and DAU-9S (RS232) cable or •...
Page 34
RH-37 6(b) - RF Troubleshooting Instructions Nokia Customer Care The setup should now look like this: The VCO chamber has a fixed shielding lid, which can only be opened by destroying it. To enable measurements with a closed lid, holes are located at positions where the supply voltage VR7, the tuning voltage Vc and the output frequency f can be measured.
Page 35
RH-37 Nokia Customer Care 6(b) - RF Troubleshooting Instructions Figure 2: VCO probe The VCO frequency is twice the Rx frequency in the GSM1800 band: = 2 * 1842.8 MHz = 3685.6 MHz = 2 * f The tuning voltage can be easily measured at the Vc input of the VCO. The corresponding hole in the shielding lid enables the voltage measurement at C7503, which shows the same DC voltage as Vc.
RH-37 6(b) - RF Troubleshooting Instructions Nokia Customer Care Even if the PLL is not working properly (Vc outside the valid range), a frequency at the output of the VCO can be detected between 3GHz and 4.4 GHz (if the VCO itself is ok and the supply voltage VR7 = 2.78V is applied).
Page 37
RH-37 Nokia Customer Care 6(b) - RF Troubleshooting Instructions Synthesizer Setup with Phoenix: Fault Finding Tree Band: GSM 1800 part 2 Mode: RX Continuous Channel: 700 Spectrum analyzer VCO out (G7500) PLL Block is functional = 3685.6 MHz Vc of VCO = 2.1..2.6V...
RH-37 Nokia Customer Care 6(b) - RF Troubleshooting Instructions DC Supply Voltage Check For a quick check of DC power supplies, refer to the diagram below. The RF power sup- plies are generated in the UEM and can be measured either in the Small Signal Chamber or in the Base Band Chamber.
Page 44
RH-37 6(b) - RF Troubleshooting Instructions Nokia Customer Care [This page left intentionally blank] Nokia Corporation Page 44 Issue 1 07/04...