© Nokia 1255_RF_Training / Jan 2006 / CFSCompany Confidential 1255 Technical Training RF...

© Nokia 1255_RF_Training / Jan 2006 / CFS Company Confidential

1255 Technical TrainingRF Troubleshooting Presentation

NMP-CDMA, San DiegoJan, 2006


Disclaimer

Materials current at time of publish and based upon most current R&D Documentation. Please refer to the latest product TB to determine further handset hardware variations if any.


Introduction

The mobile terminal uses a Qualcomm MSM6000 baseband with a CDMA single mode engine (Cellular/ 800) consisting of two primary ASICs:

• RFT6122 RF transmitter IC• RFR6122 RF receiver IC


PWB Bottom Side

Power management IC

RF transmitter

TX saw filter

power amplifier

cell duplexer

RF receiver

RX saw filter

MSM 6000 Flash IC

19.2MHz TCXO


PWB Top Side

RF connector


TX Troubleshooting


Tx System Block Diagram


Tx RF Parts Diagram

TX IC

TX Saw filter Power Amplifier

Cell Duplexer


FTM Setup for TX Troubleshooting

1. Connect RF test connector to a spectrum.

2. Set SW1 to “FTM mode” in Module Jig.3. Connect the mobile terminal to a PC via the Module Jig, and connect a power supply.4. Open CCS RF Tools software.5. The FTM dialog box appears.6. “Select COM port” to appropriate one.7. Set “Connect Phone”.8. Set “Set FTM”.9. Set “Set Band” to “CDMA800”.10. Set “Set Channel “to Channel “384”.11. Set “Set PA Range R1” to “on”12. Set TX waveform to “CDMA”13. Set “TX on/off” to “on”.14. Set “TX AGC” to “120”.

Put the PWB on the module jig. Use the following steps to configure FTM for RF troubleshooting.


Cell Tx Check from RF connectorUse the following values to check the CDMA Cell Tx functionality from IQ to RF output.1. Start FTM in Local Mode with only the Tx path turned on and “Set AGC” to “100”.2. Transmitter output power at the RF connector to be approximately equal 24dBm/1.23MHz CDMA signal of 836.52MHz .

RF Connector

FSQ26 signal analyzer settings•MEAS->CHAN PWR ACP->CP/ACP STANDARD->CDMA IS95A REV•FREQ->836.52MHZ


Tx DC Probe Points

Test Point

Description

Value

1 PA_ON2.94V for PA turning on,

0V for turning off

2 PA_R12.0V for high gain

mode,1.44V for low gain mode

3LOCK_D

ET2.96V for Lock, 0 V for

unlock

4 TX_AGC1.8V for 5dBm, 2.08V for 15dBm, 2.3V for 25dBm.

5 Tx IQ in 0.8 V With oscilloscope: 500 mV p-p

6DAC_RE

F1.83 V

7VREG_MSMP

2.95V

8VREG_R

FTX2.65V7 8

5

3

14

2

6

Table 1


Tx DC Probe Points

Test Point Description Value

RF Supply Lines Resistance to Ground

1VREG_MSMP,c705

2.95V >11kΩ to groundU700,U900,U801,U602

2 VPH_PWR,c7003.2~4.2V

>550kΩ to ground U700,U7

3VREG_MSMC,c706

2.75V >45kΩ to ground U700,U401

4VREG_MSMA,c708

2.6V >120kΩ to ground U700,U401

5 VEXT_DC,r7103.2~5.7V

~9.3kΩ to ground Q700

6VREG_TCXO,c723

2.85V >450kΩ to ground U700

7VREG_RFRX,r715

2.65V >350kΩ to ground U700,U900,U801

8VREG_RFTX,c709

2.65V >450kΩ to ground U700,U900,U801

32

41

8765

Table 2


Tx RF Probe Points

Test Point

Description Value

1 RFT6122 output 4dBm

2 PA input 2dBm

3 PA output 28dBm

4 RF connector 24dBm

5 UHF LO0dBm at 1763.04MHz

Tx RF Probe Points

4

3

21

5 Table 3


Tx path troubleshootingTx pathFaults

Measure DC test points at Table 1 and

Table 2. Is it OK?NO Check PM6610, MSM6000

YES

Measure Tx RF test points 5

at Table 3. Is it OK

NO Change RFT6122

YES

Reflow C920, FL600, C619, U7

YES



NO Reflow R903, C911



NO

NO Reflow U7

YES



YES

Reflow F600, S600Measure Tx RF test

points 4at Table 3. Is it OK

NO

NO Change U7

NO Reflow PM6610 or MSM6000

YES

Check Antenna Module

If RF Antenna feed point pad obstructed , clean the pad. Connect System Simulator to

MS antenna. Is it OK NO


Rx Troubleshooting


Rx System Block Diagram

The RFR6122 IC provides the Zero-IF receiver signal path for Cellular-CDMA reception. For this chipset, Cellular-CDMA refers to band classes 0 and 3 as defined by the cdma2000 standard, with mobile station receivers operating between 832 and 894 MHz. The Rx signal path includes the LNA, quadrature downconversion, and baseband functions.The Cellular-CDMA receive signal is routed from the antenna to the RFR6122 IC via the duplexer. The analog baseband outputs interface with one of Qualcomm’s Mobile Station MSM6000 devices that also provide status and control signaling. Integrated RX LO circuits, ideally supplemented by the RFT6122 transmitter IC, provide frequency plan flexibility and further reduce PCB parts count.


FTM setup for RX troubleshooting

1. Connect RF test connector to a spectrum.

2. Set SW1 to “FTM mode” in Module Jig.

3. Connect the mobile terminal to a PC via the Module Jig, and connect a power supply.

4. Open CCS RF Tools software.5. The FTM dialog box appears.6. “Select COM port” to appropriate one7. Set “Connect Phone”. 8. Set “Set FTM “.9. Set “Set Band” to “CDMA800”.10. Set “RF Channel “to Channel “384”.11. Set “LNA Range” to whatever

needed.



Cell Receiver Check from RF to IQ

shows the Cell spectrum with an inject tone at -75 dBm, as well as the IQ output test points. Note that DC is present on the IQ output test points. All test points should be approximately equal.

Use the following values to check the CDMA Cell Rx functionality from RF to IQ output.1. Start FTM Mode with only the Rx path turned on and set LNA_GAIN_STATE=0.2. Inject a -75 dBm CW signal of 881.82 MHz (i.e. 300 kHz offset from 881.52 MHz or 10 channels away).3. Measure a 300 kHz tuning on the analyzer. You should see a typical -52 dBm IQ tuning for CDMA Cell.

FSQ26 signal analyzer settings•RBW-> 3 kHz•VBW-> 300 Hz•Sweep Time-> 450 ms•Reference Level-> -20 dBm•FREQ-> 300 kHz•Span-> 200 kHz


3

1

2

Receiver DC Probe Points

Test Point

Description Value

1 VREG_MSMP ,r806 2.95V

2 VREG_RFRX,r801 2.6V

3 LNA BIAS,L807 2.6V

Table 4


Receiver RF Probe Points

Test Point

Description Value

1 LNA IN -28dBm

2 RX SAW INPUT -48dBm

3 RX SAW OUTPUT -51dBm

1

2

3

Table 5

In RF probe test, an external signal source of –25 dBm was injected to the RF input. Set LNA GAIN STATE = 3 .The signal was then traced throughout the receiver chains. An CMU200 call box is recommended. (Open non-signaling mode, press the SG soft button, and then select CW.) Inject a continuous wave (CW) for Cell (881.52MHz) at a fixed –25 dBm power level. Measurements were taken with the RF Probe. Signal levels are approximate, and the accuracy may be +/- 2 dB or more depending on the probe position and grounding.


Rx Path TroubleshootingRx Path Troubleshooting

Rx pathFaults

Measure DC test points at Table 4.

Is it OK?NO

YES

Measure Rx RF test points 1


NOReflow L804, C814,

RFR6122

YES

Reflow U800

YES



NO Reflow C813, L803



NO

NO Change RFR6122

Check PM6610 NO Reflow PM6610

Check Antenna Module

Connect System Simulator to MS antenna. NO

YES


RF Path Loss

• Set COM port and Input the maximum output power of the golden phone in dBm. Then, click “Start” button to run program.

• After the program is done, the path loss will be shown on the screen and recorded for the RF calibration and Call Test program. Click “Quit” for closing this program.


RF Tuning and Calibration

1. Connect RF test connector to a CMU200 or Agilent 8960.

2. Set SW1 to “FTM mode” in Module Jig.3. Connect the mobile terminal to a PC via

the Module Jig, and connect a power supply.

4. Open CCS Service SW and run RF Calibration function

5. Select “Tester Selection” Agilent 8960 or CMU200

6. Set cable loss value as the result from running “Path Loss” to Loss (dB)

7. “Select COM port” to appropriate one8. Press “Start”. 9. If tuning and calibration is successful ,

screen will shown “PASS”, otherwise, check the error code table



RF Calibration Error Code

• Error Message Table:

Error Message Upper Limit Lower Limit Debug

FAIL:TESTER Check your GPIB connection.

FAIL:COMPORT Check your COM connection.

FAIL:DVGA 3000 1700 Possible reason:Default NV table could be wrong.File system is not exist.Image version inconsistent.

FAIL:LNA0 150 100 Check Rx/Tx path components




FAIL:LOW_GAIN 25 dBm 5 dBm Synthesizer unlock

FAIL:HIGH_GAIN 27 dBm 5 dBm Synthesizer unlock

FAIL:HDET 210 120 Check Rx/Tx path components


Questions???Thank you for your attention!

© Nokia 1255_RF_Training / Jan 2006 / CFSCompany Confidential 1255 Technical Training RF...

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