Nokia Customer Care 2118 (RH-77) Mobile Terminal RF Description and Troubleshooting Issue 01 04/2005 Company Confidential ©2005 Nokia Corporation
118 (RH-77) RF Description and Troubleshooting Nokia Customer Care Contents Page Components ..................................................................................................................................................... 3 Transmitter Troubleshooting ....................................................................................................................... 5 Low Tx Power ....................................................................................................
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care Components Figure 1 and Figure 2 illustrate the main components of the 2118.
2118 (RH-77) RF Description and Troubleshooting Cell duplexer Nokia Customer Care On/Off switch Rx IC LNA+downconverter Cell isolator PA PMIC DC-DC converter Cell Rx RF SAW filter Cell Tx PA Cell Tx SAW filter Tx Up-Converter Battery converter Rx downconverter VCO VCTCXO Rx IF CDMA filter UEM UPP Flash SIM card connector Pop-port connector Figure 2: RF components (bottom) Page 4 ©2005 Nokia Corporation Company Confidential Issue 01 04/2005
Nokia Customer Care 2118 (RH-77) RF Description and Troubleshooting Transmitter Troubleshooting Low Tx Power Use Phoenix to turn on the transmitter in Local Mode, and check the following: • Verify the current (0.7 - 1A for max power, mode, and channel dependent). • Use a microscope to visually inspect the PWB for proper placement, rotation, and soldering of components.
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care 2. Click the LOCAL button in the Phone State area to put the mobile terminal into Local Mode. 3. Select the following values on the RF Main Mode dialog box: • Band = Cell (CDMA) • Channel = 384 • Mode = Rx/Tx Figure 4: RF Main Mode dialog box for Tx troubleshooting 4. Click Set. Note: Be sure that the “RF Main Mode set successfully” message appears in the status bar. 5. Select the Rho ON check box on the CDMA Control dialog box.
Nokia Customer Care 2118 (RH-77) RF Description and Troubleshooting 9. Enter 10, 13, 12, and 8 in the PIN # fields. Figure 6: General I/O dialog box for Tx troubleshooting 10. Select the boxes in the Enable column for each pin. 11. Click the Get All button. 12. Ensure that all of the pins have a value of H in the State column. (Click the L values to change them to H values.) 13.
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care Figure 7: RF PDM dialog box for Tx troubleshooting 14. Ensure that the Phone Tx Pout = +25 dBm and the current = 770-860 mA. Cell Transmitter Path Table 1 indicates the test points (see Figure 8) to probe when troubleshooting the cell transmitter path. It is recommended that you follow the steps in order.
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care Table 1: Cell Transmitter Test Points (Continued) Part* Function Typical Value/ Frequency HP85024A T8 C636L, C624T, L609B, C612L, C630B, L607B VR2 2.7 V dc Mixer, driver, and IF supply from UEM T9 C605R, C606R VAGC-Tx 0.2 to 1.8 V dc Tx AGC Control Voltage from UPP. 0.2 V = Max Gain 1.8 V = Min Gain T10 C658R, C600T VIO-Tx 1.8 V dc Supply for Digital circuits from UEM T11 C805B, C810T, C816R VBAT 3.
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care Figure 8 shows each test point for the N601 TXIC section from Table 1, “Cell Transmitter Test Points,” on page 8. Always attach a 20 dB pad (11881-60001) when probing with an HP85024A high-frequency probe. Figure 8: (Top) PWB. (Bottom left) A zoomed view of the testing points on the N601 TXIC section. (Bottom right) A zoomed view of the N601 TXIC section with part numbers.
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care Figure 9 shows each testing point for the PA section from Table 1, “Cell Transmitter Test Points,” on page 8. Always attach a 20 dB pad (11881-60001) when probing with an HP85024A high frequency probe. Figure 9: (Top) PWB. (Bottom left) A zoomed view of the testing points on the PA section. (Bottom right) A zoomed view of the PA section with part numbers.
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care Table 2: Tx AGC Tuning Steps (Continued) Tx Tuning AGC Step Tx AGC PDM Value Target Power Low Limit High Limit Tx AGC (6) -94 15 6 24 Tx AGC (7)* -280* 25 21 27 *Not an actual FlaLi tuning PDM. The PDM produces approximately 25 dBm at the antenna connector. Cell Power Amplifier The power amplifier (PA) has the DC/DC converter (PMIC device), which controls the transmitter.
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care Table 6: PMIC Measurements Pin Label Test Point Units Depends On Comments 1 EP Pin 1 1.8 UPP IC enable = GenIO 10 2 M0 Pin 2 1.8 UPP Control 0 = GenIO 12 3 M1 Pin 3 1.8 UPP Control 1 = GenIO 13 4 NC NC NC NC NC 5 FB Pin 5 0.75 - 4 M0, M1 See PA worksheet. Output to flyback inductor. 6 FB Pin 6 0.75 - 4 M0, M1 Shares PWB pad with pin 5 7 BYPVout bottomC808 0.
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care Table 7: Good Mobile Terminal PMIC Resistances (Continued) Pin Resistance 11 115 k 12 60 k 13 0.2 14 1.3 M 15 1.18 M 16 0.1 Cell IF/RF AGC and PA Control Table 8, “Cell CDMA Channel 384 (Skyworks PA),” on page 15 illustrates the PDM values and their typical values for the IF AGC, RF AGC N601 Pout, gain steps, and the PA VCC levels. This table also shows the typical power output at the RF connector.
2118 (RH-77) Nokia Customer Care RF Description and Troubleshooting Table 8: Cell CDMA Channel 384 (Skyworks PA) Tx RF AGC PDM Typical Value Test Point -290 0.45 -196 0.59 Bottom C606 -95 Tx IF AGC N601 Po PA Gain Step PDM Typical Value Test Point Typical Value Test Point -290 0.45 3 -196 0.59 Top C605 pin 1 Z601 0.75 -95 0.75 -95 0.75 -95 -48 0.83 -48 PA Vcc Conn RF Pout Gen IO 12 Gen IO 13 Typical Value Test Point PA Gain H H 3.47 C806 DM 25 H H 3.
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care Cell Power Detector The following tables illustrate the measurements required for troubleshooting the cell power detector. Table 9: Cell Power Setup Mode Tx Rx Band Chnn Rho Local On On CELL 384 On Input Chnn Tx Freq Rx Freq 384 836.52 881.
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care Table 11: Detector Reference and DC Supply label Test Point Typical Value Det Ref left-C803 2 Det Supply bottom-C257 2.
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care Tx System Block Diagram See the Schematics chapter for a 2118 transmitter schematic. Antenna TP1 RF VGA (RF AGC PDM) TP4 Bandpass PWR Amplifier Duplexer BB I LPF IQ Modulator Upconverter Tx SAW Isolator TP2 TP3 I VHF LO 0º 0º IF VGA (IF AGC PDM) UHF LO 0º From Baseband 0º To Baseband ÷2/÷4 90º Power Detector Cell RX 90º 90º 90º 457.2MHz Q 1052.
Nokia Customer Care 2118 (RH-77) RF Description and Troubleshooting Receiver Troubleshooting Rx IF Use Phoenix to perform the following steps for troubleshooting the receiver. Together with the VCO frequency and level verification, this test should be the first test for a nonworking receiver. This test verifies the entire receiver chain, from input connector to baseband output. 1. Inject a CW signal 881.82 MHz or 881.22 MHz (CH-384 offset by 300 KHz) at a fixed –75 dBm power level.
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care Figure 12: RF Main Mode dialog box for Rx IF troubleshooting 5. Click Set. Note: Be sure that the “RF Main Mode set successfully” message appears in the status bar. 6. Use a spectrum analyzer to test TP3 (I+,I-, Q+, Q-). Set the S.A to 300 KHz center frequency, 200 KHz SPAN, and +10 dBm reference level. The spectrum analyzer should read –8 dBm without any settings to the PDM. 7. Use Table 12 to configure the CDMA generator code domain.
18 (RH-77) RF Description and Troubleshooting Nokia Customer Care Table 13: Rx IF Troubleshooting (Continued) Typical Value/ Frequency HP85024A Typical Value Frequency Prod Probe Step # Part Function Comments TP3 I+, I-, Q+, Q- I/Q outputs of N700 300KHz tone for input: 881.22 MHz -69/-84 dBm 300 KHz Baseband differential outputs of the IF IC (N700). To test: set the input to 881.22 or 881.82 MHz/-75 dBm to get a 300 KHz tone when receiver is on channel 384 (881.52 MHz) TP4 C728T 19.
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care Figure 13 shows each test point as listed in Table 13. Figure 13: (Top) PWB. (Bottom left) A zoomed view of the testing points on the Rx IF section. (Bottom right) A zoomed view of the Rx IF section with part numbers.
Nokia Customer Care 2118 (RH-77) RF Description and Troubleshooting Figure 14 shows an alternate part orientation. Notice that Pin 1 is rotated 180 degrees compared to the first filter as shown in Figure 13 on page 22. All test points and values are the same.
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care Switching the Gain Use the following steps if the receiver is not working properly and you need to switch the Rx gain state. 1. Open the Phone Control dialog box. Figure 15: Phone Control dialog box for switching the Rx gain state 2. Click the LOCAL button in the Phone State area to put the mobile terminal into Local Mode. 3.
Nokia Customer Care 2118 (RH-77) RF Description and Troubleshooting 5. Connect a signal generator in CW mode (881.52 MHz, -25 dBm) to the RF connector. If you do not have a generator, use the Call Box Amps Mode RF Generator, Channel 384, -25 dBm and set the FM modulation to 100 Hz, deviation 400 Hz. 6. To switch the Rx gain states, open the RF Register R/W dialog box. Two gain states (Hi and Lo) are available in the receiver.
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care Rx RF The following Rx RF Troubleshooting table indicates the test points to probe when troubleshooting the Rx RF. It is recommended that you follow the steps in order. See Figure 18 on page 27 for an illustration of the test points. Table 14: Rx RF Troubleshooting Typical Value/ Frequency HP85024A Typical Value Frequency Prod Probe Comments Step # Part Function R1 L802R (Top side of the PWB) RF-IN -25 dBm/ 881.
Nokia Customer Care 2118 (RH-77) RF Description and Troubleshooting Antennae Connector (top side) R1 Figure 18: (Top left) PWB. (Top right) The antenna connector on the opposite side of the PWB, (Bottom left) A zoomed view of the testing points on the Rx RF section. (Bottom right) A zoomed view of the Rx RF section with part numbers.
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care Rx AGC (Cell mode) The following Rx RF AGC PDM vs. AGC Voltage table shows the Rx RF AGC PDM vs. AGC voltages in local mode on channel 384. Table 15: Rx RF AGC PDM vs. AGC Voltage PDM Typical Value Test Point -512 0.08 right R702 -400 0.260 -300 0.436 -200 0.597 -100 0.753 0 0.913 100 1.076 200 1.24 300 1.403 350 1.494 400 1.570 500 1.740 511 1.761 UNITS VDC Table 16: Rx AGC vs.
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care Table 16: Rx AGC vs. RF Pin for CELL Band (Continued) Conn RF Pin CELL RF AGC -107 0.
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care Receiver Block Diagram See the Schematics chapter for a 2118 receiver schematic. I/Q Down Converter LNA SW Control CELL IFA IF SAW CDMA BB Filter VGA BB AMP SAW To BB CDMA BB Filters LNA RFA ÷2 VHF PLL 367.2 MHz UHF VCO 1052.61-1077.
Nokia Customer Care 2118 (RH-77) RF Description and Troubleshooting Synthesizer Troubleshooting Faulty synthesizers can cause both Rx and Tx failures during tuning, in addition to the VCTCXO tuning. The following synthesizers are incorporated into the mobile terminal: • UHF (cell) PLL inside N601 IC • Tx VHF (457.2MHz) with PLL in N601 IC in Cell Mode • Tx VHF (527.2MHz) with PLL in N601 IC in PCS Mode • Rx VHF (367.
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care Figure 21: RF Main Mode dialog box for synthesizer troubleshooting 4. Click Set. Note: Be sure that the “RF Main Mode set successfully” message appears in the status bar. 5. Read register templates N601(0) bits 10 and 11 for the UHF and Tx VHF lock condition on the RF Register R/W dialog box. Figure 22: RF Register R/W dialog box for synthesizer setup 6. Read register templates N700(0) bit 11 for the RX VHF lock condition.
Nokia Customer Care 2118 (RH-77) RF Description and Troubleshooting VCTCXO Tuning The VCTCXO can be manually tuned to verify failed tuned mobile terminals, or to verify if a mobile terminal cannot make a call. This can be done with the mobile terminal in Local Mode and generating a CW signal. The frequency accuracy of the VCTCXO can be measured using an HP8960 callbox in AMPS mode, an HP4406 Tx tester, or a spectrum analyzer (preferably using a lab system 10MHz source as equipment reference).
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care Figure 24: RF Main Mode dialog box for VCTCXO troubleshooting 4. Do not use CDMA control to turn on Rho. 5. Open the BB General I/O dialog box to set the CW signal. 6. Type 10, 13, 12, and 8 in the fields in the PIN # column. Figure 25: General I/O dialog box for VCTCXO tuning 7. Click the Get All button. 8. Change the value for Pin 8 in the Source column to GenIO Output. 9.
Nokia Customer Care 2118 (RH-77) RF Description and Troubleshooting 10. The next step depends on the type of measurement equipment you are using: • HP4406 or a spectrum analyzer: Set the center frequency to 836.52MHz and the span to 2MHz. Also, establish a marker at 836.52MHz. • HP8960: Set the callbox state to AMPS, and set the channel to 384. Use the Frequency Accuracy measurement to center the VCTCXO. 11. Adjust the AFC value to center the VCTCXO on the RF PDM dialog box.
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care VCTCXO Reference Clock Figure 27 shows the 19.2 MHz VCTCXO reference clock. To To PLL Figure 27: (Top) PWB. (Bottom left) A zoomed view of the testing points on the 19.2 MHz VCTCXO reference clock. (Bottom right) A zoomed view of the 19.2 MHz VCTCXO reference clock with part numbers.
2118 (RH-77) Nokia Customer Care RF Description and Troubleshooting Synthesizer Block Diagram See the Schematics chapter for the synthesizer schematic. CELL:457.2MHz JEDI VHF UHF counter counter 367.2MHz 19.2MHz VCTCXO CELLl Band UHF VCO VHF counter 19.
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care UHF Synthesizer Following are possible causes for an incorrect UHF frequency: • Orientation of N601 • Power supplies to N601 PLL are missing or low (VR7) • Loop filter components are missing or incorrectly installed • Matching components to N601 TxLO/PLL input are missing or incorrectly installed • 19.
Nokia Customer Care 2118 (RH-77) RF Description and Troubleshooting LO PLL Figure 30: (Top) PWB. (Bottom left) A zoomed view of the N601 LO/PLL input match components on the UHF synthesizer layout (Bottom right) A zoomed view of the N601 LO/PLL input match components UHF synthesizer layout with part numbers.
2118 (RH-77) RF Description and Troubleshooting Nokia Customer Care Figure 31 shows the layout for the Rx VHF. IC with Figure 31: (Top) PWB. (Bottom left) A zoomed view of the testing points on the Rx VHF section. (Bottom right) A zoomed view of the Rx VHF section with part numbers. Tx VHF Following are possible causes for an incorrect Tx VHF frequency: • Power supplies to the PLL portion of N601IC missing or low (VR5) • Loop filter or resonator components are missing or incorrectly installed • 19.
Nokia Customer Care 2118 (RH-77) RF Description and Troubleshooting Figure 32 shows the layout for the Tx VHF. IC with Figure 32: (Top) PWB. (Bottom left) A zoomed view of the testing points on the Tx VHF section. (Bottom right) A zoomed view of the Tx VHF section with part numbers.
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