CC Technical Documentation RM-11 Series Transceivers Troubleshooting - RF (Part 2) Issue 1 02/2004 Confidential ©2004 Nokia Corporation
RM-11 Troubleshooting - RF (Part 2) CC Technical Documentation Contents Page Synthesizer Troubleshooting.......................................................................................... 3 Synthesizer Setup Using Phoenix ................................................................................4 VCTCXO Troubleshooting .........................................................................................4 UHF Synthesizer Troubleshooting ...................................................
RM-11 Troubleshooting - RF (Part 2) CC Technical Documentation Synthesizer Troubleshooting RX VHF Synthesizer Reference Divider Cell 128 PCS 128 Phase Detector 2 mA RX VHF VCO 9-Bit B Counter RF_BUS_CLK RF_BUS_DATA RF_BUS_EN1X Charge Pump Cell 53 PCS 53 Prescaler Tank 32/33 5-Bit A Counter Cell PCS VCO Band Control 12 12 UHF Synthesizer Reference Divider Cell PCS Phase Detector UHF LO Charge Pump 640 384 Splitter 4 mA 13-Bit B Counter Cell 1038 - 1064 PCS 1286 - 1323 SYNTH_LE
RM-11 Troubleshooting - RF (Part 2) CC Technical Documentation Synthesizer Setup Using Phoenix Figure 2: Phone Control dialog box 1. Click the LOCAL button on the Phone Control dialog box. 2 Use the following settings for the fields on the RF Main Mode dialog box: • UHF: Use RX/TX mode in PCS and Cell band. This allows for checking power to both RX and TX circuits. Typically, use channel 384 in Cell band and 600 in PCS band. • RX VHF: Use RX mode; one band is enough.
RM-11 Troubleshooting - RF (Part 2) CC Technical Documentation Check for the presence of the signal at the following points (use a high-impedance RF probe): • CLK19M2_B, clock reference to Batman, should be +4.5dBm • CLK19M2_R, clock reference to Robin, should be +4.5dBm • CLK19M2_UPP, clock reference to UPP, should be +7.5dBm VCTCXO To Batman PLL 19.2 MHz @ +4.5 dBm (CLK19M2_B) To Robin PLL 19.2 MHz @ +4.5 dBm (CLK19M2_R) To Baseband UPP 19.2 MHz @ +7.5 dBm (CLK19M2_UPP) VR3 = 2.78VDC VIO = 1.
RM-11 Troubleshooting - RF (Part 2) CC Technical Documentation UHF Synthesizer Troubleshooting Figure 5: UHF Synthesizer dialog box for Cell (left) and PCS (right) bands UHF LO frequency varies with channel and can be quickly calculated using the UHF Synthesizer dialog box on the RF menu. Check to see if the LO is actually locked. Set a channel and check the status of the UHF LO within a very narrow span of 100KHz. You should see the LO virtually immobile.
RM-11 Troubleshooting - RF (Part 2) CC Technical Documentation UHF Synthesizer Layout UHF PLL IC LMX2310 VCTCXO reference probing point 19.2 MHz @ +4.5 dBm Lock voltage: DC between 1V and 3V RX LO Input to Alfred Cell channel 384: 1009.62 MHz @ -2.5 dBm PCS channel 600: 2088.10 MHz @ -12 dBm Dual-band UHF VCO TX LO Buffer RF probe point, TX LO output levels: Cell channel 384: 1009.62 MHz @ -0.5 dBm PCS channel 600: 2088.
RM-11 Troubleshooting - RF (Part 2) CC Technical Documentation Loop filter components PLL in Batman Lock voltage Resonator Figure 8: RX VHF (Batman LO) Schematic RX VHF Layout Lock Voltage Probing Point: DC voltage between 1V and 2V RF probing point 256.2 MHz @ -2.
RM-11 Troubleshooting - RF (Part 2) CC Technical Documentation Incorrect RX VHF Frequency Possible causes: • Power supplies to PLL portion of Batman IC (N701) missing or low (VR7) • Loop filter or resonator components missing or incorrectly installed • 19.2MHz reference clock missing or low (C512) • Programming is incorrect • Component failure (PLL IC) TX VHF Schematic There are two fixed LOs — 346.2MHz for Cell band and 416.2MHz for PCS band. This is the first LO for up-conversion.
RM-11 Troubleshooting - RF (Part 2) CC Technical Documentation TX VHF Layout RF Probing Point: Cell: 346.2 MHz @ -6.5 dBm PCS: 416.2 MHz @-6.5 dBm Robin IC with integrated PLL Lock Voltage Probing Point: DC voltage between 1V and 2V Figure 11: TX VHF Layout Incorrect TX VHF Frequency Possible causes: Page 10 • Power supplies to PLL portion of Robin IC (N601) missing or low (VR3) • Loop filter or resonator components missing or incorrectly installed • 19.
RM-11 Troubleshooting - RF (Part 2) CC Technical Documentation Switch PCS Duplexer PCS PA WHIP ANT. 19.2 MHz CLK RX UHF LO DATA En CLK CLK TX Troubleshooting Filter & Resonator Split Band Saw Filter PCS Driver SIO PCS DVR Hi BAND VHF SYNTH PCS Balun Diplexer Isolator Lo BAND VHF PLL UP CONV Detector RF Conn TX_RF_AGC ( UPP ) Isolator CELL DVR Div By 2 CELL SAW Filter Internal ANT.
RM-11 Troubleshooting - RF (Part 2) CC Technical Documentation Transmitter Schematic 2 5 4 3 PCS Isolator PCS Duplexer PCS PA Diplexer RF Connector Cell PA 3 4 5 Cell Isolator Cell Duplexer Power Detector Figure 14: Transmitter Schematic 2 Page 12 ©2004 Nokia Corporation Confidential Issue 1 02/2004
CC Technical Documentation RM-11 Troubleshooting - RF (Part 2) TX Troubleshooting Using Phoenix 1. Use the Phone Control dialog box to turn the phone on. 2 Click the Phone State tab. 3. Highlight Local, and click the Execute button. This will put the phone into Local Mode. Figure 15: Phone Control dialog box 4.
RM-11 Troubleshooting - RF (Part 2) CC Technical Documentation 5. Click the Set button. Note: Make sure the “RF Main Mode set successfully...” message appears. 6. Open the DSP menu and select the CDMA Control option. 7. Select the Rho ON check box, and click the Execute button. Figure 17: CDMA Control dialog box 8. At this point you should be able to measure TX Pout at the RF connector using the 8960 Call Box.
RM-11 Troubleshooting - RF (Part 2) CC Technical Documentation 10.
RM-11 Troubleshooting - RF (Part 2) CC Technical Documentation Use the PDM settings from the previous section. Following are the approximate power levels you should expect for the PCS band (Channel 600): • C660 Output of Robin (N601), input to Hornet (N602) Probed power ≅-2dBm (If not, then replace Robin) • C627 Output of split-band filter (Z601) (Gain ≅10.5dB – (filter loss 2.3dB) ≅ 8.
RM-11 Troubleshooting - RF (Part 2) CC Technical Documentation Use PDM settings from the previous section.
RM-11 Troubleshooting - RF (Part 2) CC Technical Documentation RX Troubleshooting PCS RF FILTER AMPS IF FILTER PCS DUPLEX FILTER PCS RFA PCS LNA IQ DEMOD ADC AMPS I LOA BBFIL/BBAMP UHF VCO VGA DIPLEX FILTER CELL DUPLEX FILTER CELL RF FILTER Q CDMA Cell RFA Cell LNA RX IC "ALFRED" CDMA IF FILTER Batman RX Down-converter Figure 22: RM-11 RX system block diagram Receiver Schematic • An external signal source is injected to the RF input.
CC Technical Documentation RM-11 Troubleshooting - RF (Part 2) Turning on Rx Path Using Phoenix 1. Turn on Receiver Only in CDMA Mode. 2. Set to RX mode, and set the band and channel to the following values: • PCS CH = 600, RX = 1960MHz • CELL CH = 384, RX = 881.52MHz • AMPS CH = 384, RX = 881.
RM-11 Troubleshooting - RF (Part 2) CC Technical Documentation Figure 25: RF Main Mode dialog box for PCS, cell, and AMPS settings Switching Rx Gain States Using Phoenix Two gain states (Hi and Lo) are available in the receiver for CDMA and AMPS modes. Use the RF Gen I/O dialog box to change the gain state.
RM-11 Troubleshooting - RF (Part 2) CC Technical Documentation Receiver IF Troubleshooting Layout 10 9 Batman AMPS IF Crystal Filter CDMA IF SAW Filter 7 8 Figure 27: Receiver IF troubleshooting layout Issue 1 02/2004 ©2004 Nokia Corporation Confidential Page 21
RM-11 Troubleshooting - RF (Part 2) CC Technical Documentation Receiver RF Troubleshooting Layout 6 Cell RF SAW Filter 2 1 5 3 4 PCS RF SAW Filter Figure 28: Receiver RF troubleshooting layout Page 22 ©2004 Nokia Corporation Confidential Issue 1 02/2004
CC Technical Documentation RM-11 Troubleshooting - RF (Part 2) Receiver DC Troubleshooting Layout 2 3 5 4 1 Figure 29: Receiver DC troubleshooting layout 1. LO Vdd = 2.779 VDC LOA Vdd supply lines for cell and PCS 2. RFA Vdd = 2.799 VDC RFA Vdd supply line for cell band 3. C_LNA Vdd = 2.779 VDC External Vdd supply line for Cell LNA 4. P_LNA Vdd = 2.779 VDC External Vdd supply line for PCS LNA 5. IFA Vdd = 2.
RM-11 Troubleshooting - RF (Part 2) CC Technical Documentation Receiver DC Troubleshooting Layout 1 3 2 Figure 30: Receiver DC troubleshooting layout Table 1 includes the measure logic levels for the Rx front end. Table 1: Measure Logic Levels for Rx Front End (N750) Logic Inputs Voltages Modes Band (1) Gain_CTU (2) IF_SEU (3) CELL CDMA HI-GAIN 0.1 V 2.75 V 0V CELL CDMA LOW-GAIN 0.1 V 0V 0V PCS CDMA HI-GAIN 2.68 V 2.75 V 0V PCS CDMA LOW-GAIN 2.68 V 0V 0V AMPS HI-GAIN 0.1 V 2.
CC Technical Documentation RM-11 Troubleshooting - RF (Part 2) Alfred Receiver Troubleshooting Figure 31: Alfred receiver troubleshooting layout Things to keep in mind: • There is a separate LNA for 800MHz (Cell and AMPS) and 1900MHz (PCS). • Inside Alfred is the RFA again. There is a separate RFA for 800MHz (Cell and AMPS) and 1900MHz (PCS). • After RFA, there is a mixer and then the signals are separated by CDM (Cell and PCS) and AMPS. For example, if there is no IF frequency (128.
RM-11 Troubleshooting - RF (Part 2) CC Technical Documentation Receiver DC Troubleshooting Alfred Eventually, you will run into an Alfred failure that has the symptoms of high current in local mode with just the Rx turned on. There can be two common explanations for this: (1) No presence of an LO signal, and (2) input impedance drop shorting out one of the DC supply pins to the chip. IMPORTANT: YOU MUST CHECK FOR BOTH CONDITIONS BEFORE REPLACING THE CHIP.
CC Technical Documentation RM-11 Troubleshooting - RF (Part 2) Back Panel Control Signals RF-BB Interface Figure 33: Back panel control signals RF-BB interface Issue 1 02/2004 ©2004 Nokia Corporation Confidential Page 27
RM-11 Troubleshooting - RF (Part 2) Page 28 ©2004 Nokia Corporation CC Technical Documentation Confidential Issue 1 02/2004
