CCS Technical Documentation RH-27 Series Transceivers Troubleshooting - RF (Part 2) Issue 1 11/2003 Confidential ©2003 Nokia Corporation
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation Contents Page No Synthesizer Troubleshooting.......................................................................................... 3 Synthesizer Setup Using Phoenix ................................................................................4 VCTCXO Troubleshooting .........................................................................................4 UHF Synthesizer Troubleshooting ................................................
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation Synthesizer Troubleshooting RX VHF Synthesizer Reference Divider Cell PCS Phase Detector Charge Pump 128 128 2 mA RX VHF VCO 9-Bit B Counter Cell PCS RF_BUS_CLK RF_BUS_DATA RF_BUS_EN1X 53 53 Prescaler Tank 32/33 5-Bit A Counter Cell PCS 12 12 VCO Band Control UHF Synthesizer Reference Divider Cell PCS Phase Detector UHF LO Charge Pump 640 384 Splitter 4 mA 13-Bit B Counter Cell PCS 1038 - 1064 1286 - 1323 SYNTH_LE RX FRO
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation Synthesizer Setup Using Phoenix 1 Use Phone Control to put phone into Local Mode. • UHF: Use RX/TX mode in PCS and CELL band. This allows for checking power to both RX and TX circuits. Typically, use CH 384 in CELL band and 600 in PCS band. • RX VHF: Use RX mode, one band is enough. • TX VHF: Use RX/TX mode, PCS and CELL band.
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation will not power up. This signal goes to Batman, Robin, UHF PLL, and also to the UPP via a buffer amplifier (D572). 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.
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation UHF Synthesizer Troubleshooting UHF LO frequency varies with channel and can be quickly calculated using “UHF Synthesizer” Phoenix in 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. Nominal UHF LO signal levels measured with RF probe (see the following figures).
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation UHF Synthesizer Schematic UHF PLL IC Dual Band VCO Lock voltage Loop filter components UHF Synthesizer Layout VCTCXO reference probing point: 19.2MHz @ +4.5dBm UHF PLL IC LMX2310 Lock voltage: DC between 1 and 3 V RX LO input to Alfred CELL CH 384: 1009.62MHz @ –2.5dBm PCS CH 600: 2088.1MHz @ -12dBm Dual Band UHF VCO TX LO buffer RF probe point, TX LO output levels: CELL CH 384: 1009.62MHz @ –0.5dBm PCS CH 600: 2088.
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation • Power supplies to PLL IC (N507) is missing or low. • Loop filter components missing or incorrectly installed. • 19.2MHz reference clock missing or low. • Programming is incorrect. • Component failure (VCO or PLL IC). RX VHF (Batman LO) Schematic • Operates at a fixed frequency of 256.2MHz. It is the second LO for down-conversion to I and Q for baseband processing. Refer to frequency plan. • Monitor probing point at C702 for Batman LO.
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation RX VHF Layout Lock voltage probing point DC voltage between 1 and 2 V RF probing point: 256.2MHz @ -2.5 dBm Batman IC with Integrated PLL CDMA IF filter 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.
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation Lock voltage Robin Loop filter Resonator TX VHF Layout Robin IC with Integrated PLL RF probing point: CELL: 346.2MHZ @ -6.5dBm PCS: 416.2 MHz @ -6.5dBm Lock voltage Probing point DC voltage between 1 and 2 V Incorrect TX VHF Frequency Possible causes: • Power supplies to PLL portion of Robin IC (N601) missing or low (VR3).
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation • Loop filter or resonator components missing or incorrectly installed. • 19.2MHz reference clock missing or low. • Programming is incorrect. • Component failure (PLL IC). Switch PCS Duplexer PCS PA WHIP ANT. 19.
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation Transmitter Schematic 1 PCS split-band SAW Filter 1 PCS Driver PCS Band 2 PCS switch 1 Cell Driver 2 Cell SAW Filter Cell Band Robin TX Up- converter 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 Page 12 ©2003 Nokia Corporation Confidential Issue 1 11/2003
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation TX Troubleshooting Using Phoenix 1 Use Phone Control to turn phone on and select Phone State menu. Highlight “Local” and click the Execute button.
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation PCS Band Cell Band Make sure command was successful 3 Use CDMA Control under DSP menu • Select “Rho ON” and click the Execute button. Make sure command was successful At this point you should be able to measure TX Pout at the RF connector using the 8960 Call Box.
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation PCS Band TX Pout = +12dBm If you don’t see these powers, then it is time to start probing the TX path to find out where the signal stops. 4 After Local Mode/MainMode/and CDMA Control activated adjust the PDM values from under RF menu. MIN MIN MAX MAX MAX MIN NOTE: If you do not measure the correct Tx power at the RF connector, then it is time to use the RF probe and determine where the failure occurs.
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation PCS Band TX Probe Points PCS Duplexer 3 1 4 2 PCS PA 5 Use PDM settings from previous section. Here are approximate power levels you should expect for PCS BAND (Channel 600) 1. C 660 Output of Robin (N601), input to Hornet (N602) Probed power ≅-2dBm (If not, then replace Robin) 2. C 627 Output of split-band filter (Z601) (Gain ≅10.5dB – (filter loss 2.3dB) ≅ 8.2dB) Probed power ≅ 7dBm (If not, then replace Hornet) 3.
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation Cell and AMPS Band TX Probe Points 2 1 3 4 5 Use PDM settings from previous section. Here are approximate power levels you should expect for CELL BAND (Channel 384) 1. C 677 Output of Robin, Input to the Tomcat Driver Probed power ≅ -3dBm (If not, then replace Robin) 2. Pin 6 of Tomcat Driver is the output (Gain ≅ 14dB) Probed power ≅ +11dBm (If not, then replace Tomcat) 3.
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation TX AMPS Troubleshooting Using Phoenix • In Local Mode/MainMode select AMPS Band • Use PDM controls to adjust the PA, RF AND IF AGC Local Mode Mode PA Gain PDM = 229 RF AGC PDM = -416 IF AGC PDM = -137 With PDMs set to the above values: Phone TX Pout ≅ +26dBm Current ≅ 998mA NOTE: If you do not measure the correct TX power at the RF connector, then repeat Cell band “Local” mode troubleshooting to find where the failure occurs.
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation Receiver Schematic • An external signal source is injected to the RF input. Signal is then traced throughout the receiver chains. • Agilent call box 8960 is recommended. Hit Button “CALL SETUP”, soft button “Active Cell” then select “CW”. • Inject a CW signal for PCS (1960MHz) or Cell/AMPS (881.52MHz) at a fixed –25dBm power level. The numbers below indicate the general RF signal flow and probing locations.
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation Switching Rx Gain States Using Phoenix • Two Gains (Hi and Lo) States are available in the receiver for CDMA and AMPS modes Use RF Gen I/O (see the following) Page 20 ©2003 Nokia Corporation Confidential Issue 1 11/2003
CCS Technical Documentation RH-27 Troubleshooting - RF (Part 2) Hi Gain State Lo Gain State Issue 1 11/2003 Confidential ©2003 Nokia Corporation Page 21
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation Receiver IF Troubleshooting Layout 10 9 Batman AMPS IF Crystal Filter CDMA IF SAW Filter 7 8 Page 22 ©2003 Nokia Corporation Confidential Issue 1 11/2003
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation Receiver RF Troubleshooting Layout Cell RF SAW Filter 6 2 1 5 3 4 PCS RF SAW Filter Issue 1 11/2003 Confidential ©2003 Nokia Corporation Page 23
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation Receiver DC Troubleshooting Layout 2 3 5 4 1 1 LO Vdd = 2.779VDC LOA Vdd supply lines for cell and PCS 2 RFA Vdd = 2.779VDC RFA Vdd supply line for cell band 3 C_LNA Vdd = 2.779VDC External Vdd supply line for Cell LNA 4 P_LNA Vdd = 2.779VDC External Vdd supply line for PCS LNA 5 IFA Vdd = 2.
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation Receiver DC Troubleshooting Layout 1 3 2 Measure Logic Levels for Rx Front End (N750) LOGIC INPUTS VOLTAGES GAIN_CTL BAND MODES 1 IF_SEL 2 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 2.76 V 2.76 V AMPS LOW-GAIN 0.1 V 0V 2.76 V Note: If logic levels are significantly off (+/- 0.
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation Alfred Receiver Troubleshooting Things to Keep in Mind: 1 There is a separate LNA for 800MHz (Cell and AMPS) and 1900MHz (PCS). Page 26 2 Inside Alfred is the RFA again. There is a separate RFA for 800MHz (Cell and AMPS) and 1900MHz (PCS). 3 After RFA, there is a mixer and then the signals are separated by CDM (Cell and PCS) and AMPS. 4 For example, if there is no IF freq (128.1MHz), check both Cell and PCS. If only one has at 128.
RH-27 Troubleshooting - RF (Part 2) CCS 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.
RH-27 Troubleshooting - RF (Part 2) CCS Technical Documentation Back Panel Control Signals RF-BB Interface Page 28 ©2003 Nokia Corporation Confidential Issue 1 11/2003
