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Nokia 6275 Rf Description And Troubleshooting

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Nokia Customer Care
6275/6275i (RM-154)
Mobile Terminals
RF Description and
Troubleshooting
©2006 Nokia Corporation
Issue 1 - September 2006
Company Confidential

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  • Page 1 Nokia Customer Care 6275/6275i (RM-154) Mobile Terminals RF Description and Troubleshooting ©2006 Nokia Corporation Issue 1 - September 2006 Company Confidential...

  • Page 2: Table Of Contents

    6275/6275i (RM-154) RF Description and Troubleshooting Contents Page Introduction ..............................5 Preliminary RF Troubleshooting ......................6 RF Troubleshooting Equipment List ......................7 Transmitter RF Troubleshooting ......................... 8 Transmitter Schematics ..........................9 Transmitter Troubleshooting Guidelines .....................11 Transmitter Troubleshooting Setup ......................11 AMPS Tx Setup ............................12 Cell Tx Setup ............................
  • Page 3 6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting UHF CELL Tx LO (3296.16 ~ 3395.88)/4MHz Typical Spectrum ...........48 GPS Troubleshooting........................... 49 GPS RF Block Diagram ..........................49 GPS RF Schematic .............................49 GPS Troubleshooting Setup ........................50 HW Self Test Failure..........................51 Oscillator Test Failure ...........................
  • Page 4 6275/6275i (RM-154) RF Description and Troubleshooting Nokia Customer Care This page intentionally left blank. Page 4 Company Confidential Issue 1 - September 2006...

  • Page 5: Introduction

    The 6275/6275i mobile terminal is based on tri-mode, code division multiple access or “CDMA,” dual-band engine. The variants include tri-mode terminals with and without the GPS component. Note: The 6275 variant is identical to the 6275i variant, except that the GPS is not supported in the 6275 variant. UEMEK...

  • Page 6: Preliminary Rf Troubleshooting

    6275/6275i (RM-154) RF Description and Troubleshooting Coupler Diplexer Duplexer PA DC/DC converter PCS PA RX circuits Cell PA TX ASIC VCO synthesizer Bluetooth Figure 2: PWB components - bottom Preliminary RF Troubleshooting Verify the following if the mobile terminal cannot make a call: •...

  • Page 7: Rf Troubleshooting Equipment List

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting • The Preferred Roaming List (PRL) is loaded into the mobile terminal (for Normal mode). • The mobile terminal is tuned and has passed tuning. Read the tuning parameters using the Read Parameters component in Phoenix. An untuned mobile terminal has all zeros in the tuning file.

  • Page 8: Transmitter Rf Troubleshooting

    6275/6275i (RM-154) RF Description and Troubleshooting Transmitter RF Troubleshooting Following is the block diagram for the Tx RF system. Figure 3: Transmitter system block diagram Page 8 Company Confidential Issue 1 - September 2006...

  • Page 9: Transmitter Schematics

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting Transmitter Schematics The following schematics are for general reference only. See the Schematics chapter for detailed versions. FALSE_DET C7022 Z7000 L7001 B39841-B9003-E910 27nH 836.5MHz C7023 C7000 R7000 PA_INPUT_CEL C7001 C7002 L7002...
  • Page 10 6275/6275i (RM-154) RF Description and Troubleshooting Nokia Customer Care BLACKCOMB PCS duplexer PCS PA N7300 RF3448E5 C7326 Z7300 R7300 DUPLEX PA_INPUT_PCS RFin RFout LNA_PCS FILTER RFout 1 Vid C7307 L7301 NA(CX2) 3n9H IREF_PCS Iref/Vref NA(CX2) TP7300 R7310 GND/NC GND/NC 18...

  • Page 11: Transmitter Troubleshooting Guidelines

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting Transmitter Troubleshooting Guidelines Use the following guidelines when troubleshooting. • Always perform visual inspection of PCB under microscope to check proper placement, rotation, and soldering of components. • Look for the presence of a well-defined CDMA modulated signal on a spectrum analyzer at the correct frequency.

  • Page 12: Amps Tx Setup

    6275/6275i (RM-154) RF Description and Troubleshooting AMPS Tx Setup Use the following procedures to prepare for AMPS Tx troubleshooting using Phoenix. Note the 6236i variant does not support AMPS. 1. Connect the RF test connector to a spectrum analyzer. 2. Connect the mobile terminal to the PC via a test jig. (The bottom connector is a USB port.)

  • Page 13: Cell Tx Setup

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting Figure 7: AMPS Control dialog box 7. In the Function field, select Tx Control. 8. In the Set Channel field, type 384. 9. In the Power Level field, type 5. 10. Select the Transmitter ON and Use DSP 2 codes options.
  • Page 14 6275/6275i (RM-154) RF Description and Troubleshooting 5. Open the Troubleshooting menu, point to RF, and click RF Main Mode. The RF Main Mode dialog box appears. Figure 8: RF Main Mode dialog box for Cell Mode 6. Select the following values on the RF Main Mode dialog box: Band = Cell (CDMA) •...

  • Page 15: Pcs Setup

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting 11. Configure the spectrum analyzer using the following values: • Center Frequency = 836.52 MHz • Span = 100 MHz • Amplitude = 20 dBm • Attenuation = Auto • BW = Auto...

  • Page 16: Transmitter Rf Troubleshooting Procedures

    6275/6275i (RM-154) RF Description and Troubleshooting 10. Select the following values on the CDMA Control dialog box. State = Rho ON • Band = PCS • Radio Configuration = Mode 1: IS-95 Voice • Note: Do NOT select the “Set default PDM values” option.

  • Page 17: Failed Test: Tx Pa Detector

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting 3. Using an oscilloscope, check the I and Q input modulation wave forms at test points. See "Tx RF Components of the PWB" on page 19. They should all be present with an AC swing of about 500mVpp, with an offset of +1.2V.

  • Page 18: Tx Output Spectrum

    6275/6275i (RM-154) RF Description and Troubleshooting Tx Output Spectrum Following is the correct output of the mobile terminal on a spectrum analyzer with 100MHz span. Note that if you are using the AAS-10 probe with the mobile terminal connected to the call box, the amplitude should be approximately -7dBm at the antenna test point on the top of the PWB.

  • Page 19: Tx Rf Component Diagram

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting Tx RF Component Diagram Following are the Tx RF components. PCS Tx Diplexer Coupler Tx IC SAW filter PCS PA Duplexer Cell PA Cell Cell Power Cell Tx Duplexer Coupler Detector...

  • Page 20: Tx Rf Probe Points

    6275/6275i (RM-154) RF Description and Troubleshooting Tx RF Probe Points Figure 14 shows the Tx RF probe points of the PWB. Diplexer out: PCS Frequency 1880 MHz PCS +16 dBm PCS PDM: PCS TX IC out: PCS PA in: PCS PA out:...

  • Page 21: Receiver Block Diagram

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting Receiver Block Diagram Following is the Rx System block diagram. Figure 16: Receiver System block diagram Issue 1 - September 2006 Company Confidential Page 21...

  • Page 22: Receiver Schematics

    6275/6275i (RM-154) RF Description and Troubleshooting Nokia Customer Care Receiver Schematics The following schematics are for general reference only. See the Schematics chapter for detailed versions. R7160 SHORT_CIRCUIT C7165 Cell RF SAW filter L7165 12nH Z7160 C7166 881.52MHz R7164 C7167...
  • Page 23 6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting F_REF_RX VHF Loop Filter R7100 C7100 C7101 C7102 330n R7101 470R N7100 BATMAND_PBFREE VCC_CH TEST_OUT GND_CH C7103 C7104 CLK19M2 RF_BUS_CLK PD_LO2 RFBusClk R7102 RESO_LO2 RF_BUS_ENABLE Rx VHF Lo Lock Voltage RX_VHFBUF_p...

  • Page 24: Rf Agc Status

    6275/6275i (RM-154) RF Description and Troubleshooting RF AGC Status When configuring the values on the RF AGC Status dialog box, note the following: • The RF AGC status functionality only works in Call Mode. • In the PLL Lock Status area, bright green indicates a locked PLL and dark green indicates an unlocked PLL.

  • Page 25: Turning On The Rx Path

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting Turning on the Rx Path Use the following steps to turn on the Rx path using Phoenix. 1. On the Phone Control dialog box, click the LOCAL button in the Phone State area to put the mobile terminal into Local Mode.
  • Page 26 6275/6275i (RM-154) RF Description and Troubleshooting AMPS Cell Figure 21: RF Main Mode dialog boxes for AMPS, Cell, and PCS Page 26 Company Confidential Issue 1 - September 2006...

  • Page 27: Switching The Rx Gain States

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting Switching the Rx Gain States Use the RF Gen I/O dialog box to switch the gain state (Hi and Lo) for CDMA and AMPS modes. Hi Gain (Default) State at power up...

  • Page 28: Receiver Rf Probe Points

    6275/6275i (RM-154) RF Description and Troubleshooting Receiver RF Probe Points IFA_in (to RX FE RFIC) Cell CH384 (to RF SAW) 128.1 MHz @ -15 dBm (HG) 881.52MHz @ -20 dBm (HG) 128.1 MHz @-32 dBm (LG) 881.52MHz @ -36 dBm (LG)

  • Page 29: Receiver If Probe Points

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting Receiver IF Probe Points IF VHF lo 256.2 MHz AMPS_IF_P and N (to RX IC) 128.1MHz AMPS IF (to MCF) 128.1MHz -2.5 dBm (when locked) CELL -23 dBm (HG) -41 dBm (LG)

  • Page 30: Receiver Dc Probe Points

    6275/6275i (RM-154) RF Description and Troubleshooting Receiver DC Probe Points VR4 = 2.7 VDC RX RF Lo lock voltage 1.2 to 1.7 VDC NOTE: There is no part installed here. There are only two pads. LO Vdd = 2.7 VDC LO...

  • Page 31: Receiver Logic Input Voltages

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting Receiver Logic Input Voltages Measure logic levels for Rx Front-End (N7160). Figure 26 shows the receiver logic input voltages. Figure 26: Receiver logic input voltage test points Table 5 includes the logic levels for the N7160.
  • Page 32 6275/6275i (RM-154) RF Description and Troubleshooting For example, if there is no IF frequency (128.1MHz) check both Cell and PCS. If only one has 128.1MHz at L7162, ensure that IF_SEL is working. If it is, then replace the Rx Front-end IC due to a bad RFA.

  • Page 33: Synthesizer Troubleshooting

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting Synthesizer Troubleshooting Faulty synthesizers can cause both Rx and Tx failures during tuning, in addition to the VCTCXO tuning. However, first check for the presence of various LO signals and their proper levels.

  • Page 34: Synthesizer Block Diagram

    6275/6275i (RM-154) RF Description and Troubleshooting Synthesizer Block Diagram 2) UHF Lo Cell CH384 @1009.62 MHz CH600 @ 2088.1 MHz 3) Rx VHF Lo 256.2 MHz N7001 N7160 N7200 1) VCTCXO 19.2 MHz 4) Tx UHF Lo 3395.88 MHz 3819.90 MHz...

  • Page 35: Synthesizer Schematics

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting Synthesizer Schematics The following schematics are for general reference only. See the Schematics chapter for detailed versions. VCTCXO with AFC control UHF PLL IC UHF Loop filter UHF VCO Figure 29: Synthesizer schematic...

  • Page 36: Synthesizer Troubleshooting Setup

    6275/6275i (RM-154) RF Description and Troubleshooting Synthesizer Troubleshooting Setup Use the following steps to troubleshoot the synthesizer using Phoenix: 1. On the Phone Control dialog box, click the LOCAL button in the Phone State area to put the mobile terminal into Local Mode.

  • Page 37: Incorrect Pll Frequencies

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting Figure 31: Phone Control dialog box Incorrect PLL Frequencies Following are some possible causes for incorrect PLL frequencies: • Power supplies to PLL portion • Control line to VCO • Loop filter or resonator components missing or incorrectly installed •...

  • Page 38: Afc Voltage Troubleshooting

    6275/6275i (RM-154) RF Description and Troubleshooting Lock voltage: AFC voltage: VCTCXO 19.2MHz clocks: DC between 1 and 3 V DC between 0.8 and 3.4 V, -9 dBm to UHF PLL 1.3V for PDM 0 S/B 1.2V at center frequency CLK19M2_TIKU to BB 0.8 V for PDM -1024...

  • Page 39: Vctcxo Manual Tuning

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting Figure 34 shows a partial schematic of the R7201. R7201 Figure 34: Partial schematic showing the R7201 2. Measure the DC voltage at R7201. The following typical voltages are observed. •...
  • Page 40 6275/6275i (RM-154) RF Description and Troubleshooting 6. Use the RF PDM component to adjust the AFC to center the VCTCXO. The tuning range is approximately ±10kHz. 7. Adjust the AFC so that the output signal is within ±150MHz. If using a spectrum analyzer, narrow the span to 1kHz or less.

  • Page 41: Uhf Synthesizer Schematic

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting UHF Synthesizer Schematic UHF PLL IC Dual-band UHF VCO Loop filter Lock voltage Figure 37: UHF Synthesizer Schematic UHF Synthesizer Troubleshooting The UHF LO frequency varies with the channel and can be calculated using the Frequency Calculator dialog box in the Phoenix RF component.
  • Page 42 6275/6275i (RM-154) RF Description and Troubleshooting 5. Check the RF return at R7210. Figure 38: Frequency Calculator in Phoenix Page 42 Company Confidential Issue 1 - September 2006...

  • Page 43: Pcs Uhf Lo Ch600 Typical Spectrum

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting PCS UHF LO CH600 Typical Spectrum Figure 39: PCS UHF LO Typical Spectrum Rho and UHF LO Measure the signal purity of the UHF LO, checking the spur level offset from the carrier.

  • Page 44: Cell Uhf Lo Ch384 Typical Spectrum

    6275/6275i (RM-154) RF Description and Troubleshooting CELL UHF LO CH384 Typical Spectrum Figure 40: CELL UHF LO Typical Spectrum Rho and UHF LO First measure the signal purity of the UHF LO, look at spur level offset from the carrier.

  • Page 45: Rx Vhf Lo (Rx Back-End Ic) Troubleshooting

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting Rx VHF LO (Rx Back-End IC) Schematic Loop filter components Lock voltage PLL in RX RFIC Resonator Figure 41: Rx UHF LO (Rx Front-End) schematic Rx VHF LO (Rx Back-End IC) Troubleshooting The VHF LO operates at a fixed frequency of 256.2MHz.

  • Page 46: Tx Uhf Lo Schematic

    6275/6275i (RM-154) RF Description and Troubleshooting Tx UHF LO Schematic The following partial schematic is for general reference only. See the Schematics chapter for complete detailed versions. Loop filter components Lock voltage Figure 43: Tx UHF LO schematic Tx UHF LO (Tx IC) Troubleshooting There are two fixed LOs, 3296.16~3395.88MHz for cell band and 3700~3819.90MHz for...

  • Page 47: Uhf Pcs Tx Lo (3700 ~ 3819.90)/2Mhz Typical Spectrum

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting UHF PCS Tx LO (3700 ~ 3819.90)/2MHz Typical Spectrum Figure 45: UHF PCS Tx LO Typical Spectrum Following are the keys observations: • The following Ref Spurs • 50kHz offset –59dBc Analyzer settings: •...

  • Page 48: Uhf Cell Tx Lo (3296.16 ~ 3395.88)/4Mhz Typical Spectrum

    6275/6275i (RM-154) RF Description and Troubleshooting UHF CELL Tx LO (3296.16 ~ 3395.88)/4MHz Typical Spectrum Figure 46: UHF CELL Tx LO Typical Spectrum Following are the keys observations: • The following Ref Spurs • 30kHz offset –65dBc Analyzer settings: • Center: 836.52MHz •...

  • Page 49: Gps Troubleshooting

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting GPS Troubleshooting GPS RF Block Diagram Figure 47: GPS block diagram GPS RF Schematic The following schematic is for general reference only. See the Schematics chapter for a detailed version. GPS TCXO...

  • Page 50: Gps Troubleshooting Setup

    6275/6275i (RM-154) RF Description and Troubleshooting GPS Troubleshooting Setup Use the following steps to set up GPS signal using Phoenix. 1. On the Phone Control dialog box, click the LOCAL button in the Phone State area to put the mobile terminal into Local Mode.

  • Page 51: Hw Self Test Failure

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting 4. Open the Troubleshooting menu, and click GPS Quick Test. The GPS Control dialog box appears Figure 51: GPS Control dialog box 5. In the Test State field, ensure that Galvanic is selected.

  • Page 52: Gps Dc Test Points

    6275/6275i (RM-154) RF Description and Troubleshooting Inspect all GPS Circuit elements around N6251. 4. If the elements pass a visual inspection and the RF is good, replace the GPS RF IC (N6251). GPS DC Test Points GPS TCXO out TCXO_VCC 2.8V 16.368MHz...

  • Page 53: Gps Rf Troubleshooting Setup

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting GPS RF Troubleshooting Setup Use the following steps to troubleshoot the GPS receiver. 1. On the GPS Control dialog box, click Receiver On. Figure 53: Turning on the GPS receiver on the GPS Control dialog box 2.

  • Page 54: Gps Rf Probe Points

    6275/6275i (RM-154) RF Description and Troubleshooting GPS RF Probe Points GPS TXCO 16.368MHz TPS TCXO out 16.368MHz -3 dBm First RF filter out -65 dBm First RF filter in -62 dBm 2nd RF filter out GPS LNA in -46 dBm...

  • Page 55: Fm Radio Troubleshooting

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting FM Radio Troubleshooting FM Radio Schematic The following schematic is for general reference only. See the Schematics chapter for a detailed version. Loop filter and VCO FM radio IC Antenna matching...

  • Page 56: Fm Radio Parts Layouts

    6275/6275i (RM-154) RF Description and Troubleshooting 7. With the universal headset connected, repeat steps 1—5. • If there is a signal present, the FM Radio is working properly. • If there is no static sound present, refer to the “Audio” section of the Baseband Description and Troubleshooting chapter for more information.

  • Page 57: Bluetooth Troubleshooting

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting Bluetooth Troubleshooting Bluetooth Schematic The following schematic is for general reference only. See the Schematics chapter for a detailed version. Bluetooth antenna connector SAW filter Bluetooth ASIC Figure 57: Bluetooth schematic...

  • Page 58: Test Setup 1

    6275/6275i (RM-154) RF Description and Troubleshooting Test Setup 1 Open the BT/WLAN menu, and click Bluetooth Locals. If the Phoenix connection to the mobile terminal’s BT ASIC is ok, text such as “MCM Software”, “MM Software” is displayed in the Version Information window.

  • Page 59: Test Setup 2

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting Test Setup 2 After obtaining the version information, select Run to do a quick check on the BT ASIC. The results of each self-test are displayed in the Self Tests window. If any test fails, BT ASIC is not working properly.

  • Page 60: Test Setup 3

    6275/6275i (RM-154) RF Description and Troubleshooting Test Setup 3 1. After passing the self-test, setup the JBT-3, JBT-9 or a later version BT box. 2. Type the BT box’s device address into the Counterpart BT Device Address window. 3. Select Run BER Test to run the BER loopback test. The BER result is visible in the BER Test Results window.

  • Page 61: Test Setup 4

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting Test Setup 4 If the mobile terminal’s BT sensitivity is not good or the setup is not calibrated (correlated) correctly, the %BER > 0.1% which results in an error. Make sure the setup is good (correlated with a golden mobile terminal), then see Item 2 in "Bluetooth...

  • Page 62: Test Setup 5

    6275/6275i (RM-154) RF Description and Troubleshooting Test Setup 5 If the mobile terminal is placed too far or the BT Tx or the Rx has problem, one of the following error messages is visible. (See Item 2 of "Bluetooth flowchart" on page 63).

  • Page 63: Bluetooth Troubleshooting Flowchart

    6275/6275i (RM-154) Nokia Customer Care RF Description and Troubleshooting Bluetooth Troubleshooting Flowchart Replace BT ASIC (N6000) when a particular row is still not ok at the end of a branch. Figure 60: Bluetooth flowchart Issue 1 - September 2006 Company Confidential...

  • Page 64: Bluetooth Dc And Rf Probe Points

    6275/6275i (RM-154) RF Description and Troubleshooting Bluetooth DC and RF Probe Points Figure 61 shows the Bluetooth DC and RF probe points. VDD_VCO and VDD_RADIO VDD_ANA 1.8V 1.8V 1.8V RF IN/OUT Bluetooth Filter Bluetooth ASIC VDD_VCO and Vbatt 1.8V VDD_RADIO 1.8V...

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