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Nokia 2125 Troubleshooting Manual

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Nokia Customer Care
2125/2125i/2126/2126i/2128i (RH-71)
Mobile Terminals
RF Description and
Troubleshooting
©2005 Nokia Corporation
ISSUE 1 08/2005
Company Confidential

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Summary of Contents for Nokia 2125

  • Page 1 Nokia Customer Care 2125/2125i/2126/2126i/2128i (RH-71) Mobile Terminals RF Description and Troubleshooting ©2005 Nokia Corporation ISSUE 1 08/2005 Company Confidential...

  • Page 2: Table Of Contents

    2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting Contents Page Component Layouts ............................3 Phoenix Setup..............................5 Tx Troubleshooting ............................7 Main Tx Components ..........................7 Cell Transmitter Block Diagram ....................... 8 Tx DC Test Points ............................9 Tx RF Test Points ............................11 TX DC Test Points ............................13...

  • Page 3: Component Layouts

    2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting Component Layouts Figure 1 Figure 2 show the main components of the 2125/2125i/2126/2126i/2128i. Cell RF connector Figure 1: Component layout (top) ©2005 Nokia Corporation ISSUE 1 08/2005 Company Confidential Page 3...
  • Page 4 2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting N7160 Rx Cell Rx SAW filter front-end IC Diplexer PCS Rx SAW Cell duplexer PCS duplexer GPS RF filter (1) Cell PA AMPS IF XTal filter GPS LNA PCS PA GPS RF connector CDMA IF...

  • Page 5: Phoenix Setup

    2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting Phoenix Setup Use the following steps to configure Phoenix for RF troubleshooting. 1. Connect RF test connector to a call box. 2. Connect the mobile terminal to a PC via the bottom connector, and connect a power supply.
  • Page 6 2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting Nokia Customer Care Table 1: Phoenix Configuration Cell AMPS 1. On the RF Main Mode dialog box: 1. On the RF Main Mode dialog box: 1. On the AMPS Control dialog box: • Band = Cell (CDMA) •...

  • Page 7: Tx Troubleshooting

    2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting Tx Troubleshooting Main Tx Components Power duplexer detector coupler PCS TX SAW filter PCS PA Cell duplexer Cell coupler Cell TX SAW filter Cell PA N7000 TX IC Figure 4: Tx components ©2005 Nokia Corporation...

  • Page 8: Cell Transmitter Block Diagram

    2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting Nokia Customer Care Cell Transmitter Block Diagram Figure 5: Tx system block diagram ©2005 Nokia Corporation Page 8 Company Confidential ISSUE 1 08/2005...

  • Page 9: Tx Dc Test Points

    2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting Tx DC Test Points VBATT PCS VBATT Cell Figure 6: Tx DC test points ©2005 Nokia Corporation ISSUE 1 08/2005 Company Confidential Page 9...
  • Page 10 2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting Table 2 shows the Tx DC test points shown in Figure Table 2: Tx DC Test Points Test Point Description Value AGC 1 From 0.1 to 1.8 V AGC 2 From 0.1 to 1.8 V 2.8 V...

  • Page 11: Tx Rf Test Points

    2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting Tx RF Test Points Figure 7: Tx RF Test Points ©2005 Nokia Corporation ISSUE 1 08/2005 Company Confidential Page 11...
  • Page 12 2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting Table 3 shows the test points shown in Figure Table 3: Tx RF Test Points Test Point Description Value Tx IQ in with oscilloscope 500 mV p-p with +1.2 V offset Tx UHF LO Cell: 3346.08 MHz, -57 dBm...

  • Page 13: Tx Dc Test Points

    2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting TX DC Test Points Figure 8: Bottom side Tx DC test points Table 4 shows the Tx DC test points shown in Figure Table 4: Tx DC Test Points and RF Supply Line Resistance to Ground...
  • Page 14 2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting Table 4: Tx DC Test Points and RF Supply Line Resistance to Ground (Continued) Test Description Value RF Supply Lines Resistance to Ground* Point VR1A 4.75 V (synthesizer) Ω UHF PLL >100k to ground VBATT From 3.2 to 4.7 V...

  • Page 15: Receiver Troubleshooting

    2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting Receiver Troubleshooting Rx System Block Diagram Figure 9: Rx RF system diagram ©2005 Nokia Corporation ISSUE 1 08/2005 Company Confidential Page 15...

  • Page 16: Cell Receiver Check From Rf To Iq

    2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting Cell Receiver Check from RF to IQ Use the following values to check the CDMA Cell Rx functionality from RF to IQ output. 1. Start Phoenix in Local Mode with only the Rx path turned on.

  • Page 17: Pcs Receiver Check From Rf To Iq

    2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting RX_QN RX_IP RX_IN RX_QP Figure 11: Cell spectrum (left) and IQ output test points (right) PCS Receiver Check from RF to IQ Use the following values to check the PCS receiver functionality from RF to IQ output.
  • Page 18 2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting PCS I Q Output Trace A Trace A 503 kHz -22.4500 dBm -100 Centre: 500 kHz Atten: 10 dB Span: 200 kHz Res BW: 3 kHz Vid BW: 3 kHz Sweep: 100 ms 5/5/2004 3:37:55 PM PcsIQ.spt...

  • Page 19: Amps Receiver Check From Rf To Iq

    2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting AMPS Receiver Check from RF to IQ Use the following steps to check the AMPS receiver functionality from RF to IQ output. 1. Start Phoenix in Local Mode with only the Rx path turned on.
  • Page 20 2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting RX_QN RX_IP RX_IN RX_QP Figure 15: AMPS spectrum (left) and IQ output test points (right) ©2005 Nokia Corporation Page 20 Company Confidential ISSUE 1 08/2005...

  • Page 21: Receiver Dc Test Points

    2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting Receiver DC Test Points Cell RF SAW filter AMPS IF Xtal filter CDMA IF SAW filter PCS RF SAW filter Figure 16: Rx DC troubleshooting test points ©2005 Nokia Corporation ISSUE 1 08/2005...

  • Page 22: Receiver Rf Test Points

    2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting Table 5 includes the descriptions and values for Rx DC troubleshooting test points shown Figure Table 5: Rx DC Test Points Test Description Value Point LO Vdd 2.6 VDC LO Amp Vdd supply lines for Cell and PCS RFA Vdd 2.8 VDC RF Amp Vdd supply line for Cell band...
  • Page 23 2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting Cell RF SAW filter PCS RF SAW filter Figure 17: Receiver RF troubleshooting test points Table 6 includes the descriptions and values for Rx RF troubleshooting test points shown Figure Table 6: Rx RF Troubleshooting Values...
  • Page 24 2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting Table 6: Rx RF Troubleshooting Values (Continued) Test Description Value Point IF MIX OUT (from N7160) High gain: 128.1MHz at -20 dBm Low gain: 128.1MHz at -37 dBm IFA_in (to N7160) High gain: 128.1MHz @ -15 dBm Low gain: 128.1MHz @ -32 dBm...

  • Page 25: Receiver If Test Points

    2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting Receiver IF Test Points Cell RF SAW filter AMPS IF Xtal filter CDMA IF SAW filter PCS RF SAW filter Figure 18: Rx IF troubleshooting test points ©2005 Nokia Corporation ISSUE 1 08/2005...
  • Page 26 2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting Table 7 includes the descriptions and values for Rx IF troubleshooting test points shown Figure Table 7: Rx IF Troubleshooting Values Test Description Value Point CDMA IF (to SAW)128.1 MHz Cell channel 384: • High gain: -6 dBm •...

  • Page 27: Receiver Logic Input Voltages

    2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting Receiver Logic Input Voltages Following are the measure logic levels for the Rx front end (N7160). Figure 19: Rx logic input voltages Table 8 includes the logic level values for the Rx front end.

  • Page 28: Synthesizer Troubleshooting

    2125/2125i/2126/2126i/2128i (RH-71) 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. The 19.2 MHz reference clock is needed for the mobile terminal to power up.

  • Page 29: Synthesizer Block Diagram

    2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting Synthesizer Block Diagram Figure 20: Synthesizer block diagram Table 9 includes the component values shown in Figure Table 9: Synthesizer Block Diagram Component Values Item Description Value VCTCXO 19.2 MHz UHF LO 1009.62 MHz (Cell channel 384)

  • Page 30: 19.2 Mhz Vctcxo Reference Clock

    2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting 19.2 MHZ VCTCXO Reference Clock The VCTCXO frequency is a 19.2 MHz reference signal. Without 19.2 MHz, the mobile terminal does not power up. This signal goes to N7100, N7000, UHF PLL, and the UPP. Use a high impedance probe to check for the presence of the signal at the following points: •...

  • Page 31: Vctcxo Manual Tuning

    2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting 2. Open the RF PDM dialog box component in RF. Figure 22: RF PDM dialog box for AFC measurement Typical voltages observed are as follows: • AFC PDM[0] = 1.3 V •...
  • Page 32 2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting Use the following steps to set up a CW signal: 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 33 2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting 7. Use RF PDM to adjust the AFC to center the VCTCXO. The tuning range is approximately +/- 10kHz. Adjust the AFC so that the output signal is within +/-150Hz. If using the spectrum analyzer, narrow the span to 1 kHz or less.
  • Page 34 2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting Figure 26: Tx output for PCS channel 600 at 25C ©2005 Nokia Corporation Page 34 Company Confidential ISSUE 1 08/2005...

  • Page 35: Vctcxo Test Points

    2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting VCTCXO Test Points Figure 27: VCTCXO test points ©2005 Nokia Corporation ISSUE 1 08/2005 Company Confidential Page 35...

  • Page 36: Receiver Uhf Synthesizer

    2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting Table 10 shows the values and description for the VCTCXO test points in Figure Table 10: VCTCXO Test Point Values and Descriptions Test Description Point CLK19M2_UPP to UPP CLK19M2_GPS to GPS module VR3: 2.8 V AFC voltage: DC between 1 and 3 V: •...
  • Page 37 2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting The Frequency Calculator dialog box appears. Figure 28: Frequency Calculator dialog box for Cell (top) and PCS (bottom) 2. Check to see if the LO is locked. Set a channel and check the output of the UHF LO at L502 within a very narrow span of 100 KHz.
  • Page 38 2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting Figure 29: UHF synthesizer test points Table 11 shows the values and description for the UHF synthesizer test points in Figure Table 11: UHF Synthesizer Test Point Values and Descriptions Test Description Values Point 2.8 V...

  • Page 39: Rx Vhf Lo

    2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting Table 11: UHF Synthesizer Test Point Values and Descriptions (Continued) Test Description Values Point Lock voltage DC between 0.8 and 3.4 V, S/B 1.2 V at center frequency BAND_SEL_VCO Cell = 0 VDC PCS = 2.8 VDC...

  • Page 40: Rx Vhf Lo (N7100) Schematic

    2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting Nokia Customer Care Rx VHF LO (N7100) Schematic The following partial schematic is for general reference only. See the Schematics chapter for a detailed version. Loop filter components Lock voltage PLL in N7100 Resonator Figure 30: Rx VHF LO (N7100) schematic (partial view) ©2005 Nokia Corporation...

  • Page 41: Tx Uhf Lo

    2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting Figure 31 shows the Rx VHF LO test points. Figure 31: Rx VHF LO test points Table 12 gives the description and values for the test points as shown in Figure...

  • Page 42: Tx Uhf Lo Schematic

    2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting Nokia Customer Care TX UHF LO Schematic The following partial schematic is for general reference only. See the Schematics chapter for a detailed version. Lock voltage Loop filter Figure 32: Tx UHF LO schematic (partial view) ©2005 Nokia Corporation...
  • Page 43 2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting Figure 33 shows the Tx UHF LO test points. Figure 33: Tx UHF LO (N7000) test points Table 13 gives the description and values for the test points as shown in...

  • Page 44: Gps Rf Troubleshooting

    2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting Nokia Customer Care GPS RF Troubleshooting Following is the GPS RF block diagram. Figure 34: GPS RF block diagram ©2005 Nokia Corporation Page 44 Company Confidential ISSUE 1 08/2005...

  • Page 45: Gps Rf General Testing

    2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting GPS RF General Testing In radiated testing the CW level has to be higher because of the attenuation in pad + cable + coupler. With a -20 dB pad, the signal level in the signal generator is ~ -110 dBm + cable attenuation + 20 dB + 18 dB.

  • Page 46: Self-Test Failure

    2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting 3. Open the Troubleshooting menu, and click GPS Control. The GPS Control dialog box appears. Figure 37: GPS Control dialog box 4. Select GPS Quick Test in the Function area, and ensure that the Test Mode area shows a value of Galvanic.
  • Page 47 2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting Figure 38: GPS test points ©2005 Nokia Corporation ISSUE 1 08/2005 Company Confidential Page 47...

  • Page 48: Gps Rf Test Points

    2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting Table 14 gives the description and values for the test points as shown in Figure Table 14: GPS Test and DC Test Point Values Test Description Value (V) Point VDD_IO_GPS TCXO Vcc LNA Vcc...
  • Page 49 2125/2125i/2126/2126i/2128i (RH-71) Nokia Customer Care RF Description and Troubleshooting Figure 40: GPS RF test points ©2005 Nokia Corporation ISSUE 1 08/2005 Company Confidential Page 49...
  • Page 50 2125/2125i/2126/2126i/2128i (RH-71) RF Description and Troubleshooting Table 15 includes the values for the test points in Figure Table 15: GPS RF Test Point Values Test Description Values (dBm) Point 1st RF filter in 1st RF filter out GPS LNA in...

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