Nokia rm193, 2865, 2865i RF Description and Troubleshooting

Nokia Customer Care 2865/2865i (RM-193)

Mobile Terminal

RF Description and

Troubleshooting

ISSUE 2 - October 2006

Company Confidential

©2006 Nokia Corporation

2865/2865i (RM-193)
RF Description and Troubleshooting
Contents		Page
2865/2865i Mobile Terminal.......................................................................................................................		5
RF Components ...............................................................................................................................................		6
Preliminary RF Troubleshooting..................................................................................................................		8
RF Troubleshooting Equipment List...........................................................................................................		8
Transmitter RF Troubleshooting .................................................................................................................		9
Transmitter Block Diagram .......................................................................................................................		9
Transmitter Schematics ...........................................................................................................................		10
Transmitter Troubleshooting Guidelines .............................................................................................		12
Transmitter Troubleshooting Setup ......................................................................................................		12
AMPS Tx Setup ..................................................................................................................		..................... 13
Cell Tx Setup .................................................................................................................................		.......... 15
PCS Setup.......................................................................................................................................		.......... 17
Transmitter RF Troubleshooting Procedures ......................................................................................		19
Failed Test: Tx PA Detector ....................................................................................................		............. 20
Tx Output Spectrum.............................................................................................................		................. 21
Tx RF Component Diagram ........................................................................................................		......... 22
Tx DC Probe Points .............................................................................................................		................... 22
Tx RF Probe points .............................................................................................................		.................... 23
DC Test Points................................................................................................................................		......... 23
Receiver RF Troubleshooting ....................................................................................................		................ 24
Receiver Block Diagram ...........................................................................................................................		25
Receiver Schematics .................................................................................................................................		26
RF AGC Status ............................................................................................................................................		28
Turning on the Rx Path ............................................................................................................................		29
Switching the Rx Gain States ................................................................................................................		31
Checking AMPS from RF to IQ ...............................................................................................................		32
Checking CDMA Cell Receiver from RF to IQ ....................................................................................		34
Checking CDMA PCS Receiver from RF to IQ ....................................................................................		36
Receiver Diagnostic Signal Tracing ......................................................................................................		37
Receiver RF Probe Points .......................................................................................................		.............. 38
Receiver IF Probe Points ......................................................................................................		............... 38
Receiver DC Probe Points ......................................................................................................		............. 39
Receiver Logic Input Voltages ................................................................................................................		40
Rx Front-End Receiver Troubleshooting .............................................................................................		41
Synthesizer Troubleshooting ....................................................................................................		................ 43
Synthesizer Block Diagram .....................................................................................................................		44
Synthesizer Schematics ...........................................................................................................................		44
Synthesizer Troubleshooting Setup ......................................................................................................		46
Incorrect PLL Frequencies......................................................................................................		.............. 47
VCTCXO Troubleshooting .........................................................................................................................		47
AFC Voltage Troubleshooting .................................................................................................................		48
VCTCXO Manual Tuning ...........................................................................................................		............ 49
UHF Synthesizer Schematic ....................................................................................................................		51
UHF Synthesizer Troubleshooting .........................................................................................................		52
PCS UHF LO CH600 Typical Spectrum .................................................................................................		53
Rho and UHF LO .................................................................................................................		.................... 53
CELL UHF LO CH384 Typical Spectrum ...............................................................................................		54
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		2865/2865i (RM-193)
Nokia Customer Care	RF Description and Troubleshooting
Rho and UHF LO .................................................................................................................		.................... 54
Rx VHF LO (Rx Back-End IC) Troubleshooting ...................................................................................		55
Tx UHF LO Schematic ...............................................................................................................................		57
Tx UHF LO (Tx IC) Troubleshooting .......................................................................................................		58
UHF PCS Tx LO (3700 ~ 3819.90)/2MHz Typical Spectrum ..........................................................		59
UHF CELL Tx LO (3296.16 ~ 3395.88)/4MHz Typical Spectrum ...................................................		60
GPS Troubleshooting............................................................................................................		....................... 61
GPS RF Block Diagram .............................................................................................................................		61
GPS RF Schematic .....................................................................................................................................		61
GPS Troubleshooting Setup ....................................................................................................................		63
HW Self Test Failure...........................................................................................................		................... 64
Oscillator Test Failure ........................................................................................................		................... 64
CW (Mode 3) Test Failure .......................................................................................................		............. 64
GPS DC Test Points.............................................................................................................		................... 65
GPS RF Troubleshooting Setup...................................................................................................		........ 66
GPS RF Probe Points............................................................................................................		.................. 67
FM Radio Troubleshooting .......................................................................................................		................. 68
FM Radio Schematic .................................................................................................................................		68
FM Radio Testing - Pop-Port Headset and UHJ Headset ...............................................................		69
FM Radio Parts Layouts ...........................................................................................................................		70
FM Radio Probe Points .............................................................................................................................		71
Bluetooth Troubleshooting ......................................................................................................		................. 72
Bluetooth Schematic ................................................................................................................................		72
Bluetooth Troubleshooting .....................................................................................................................		73
Test Setup 1...................................................................................................................................		.......... 73
Test Setup 2...................................................................................................................................		.......... 74
Test Setup 3...................................................................................................................................		.......... 75
Test Setup 4...................................................................................................................................		.......... 76
Test Setup 5...................................................................................................................................		.......... 77
Bluetooth Troubleshooting Flowchart .................................................................................................		78
Bluetooth DC and RF Probe Points .......................................................................................................		79

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RF Description and Troubleshooting	Nokia Customer Care

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Company Confidential

ISSUE 2 - October 2006

					2865/2865i (RM-193)
Nokia Customer Care					RF Description and Troubleshooting

2865/2865i Mobile Terminal

The 2865/2865i mobile terminal is based on tri-mode, code division multiple access (CDMA) dual-band engine. The variants include tri-mode terminals with and without the GPS component.

Figure 1: 2865/2865i mobile terminal

Note: The 2865 variant is identical to the 2865i variant, except that the GPS is not supported in the 2865 variant.

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RF Description and Troubleshooting

RF Components

Following are the components of the RF as shown of the bottom and top PWB boards.

Antenna Connector Pad

GPS TCXO

BB

Power Detector

RF

GPS section

Diplexer

PCS Duplexer

GPS connector

Cell Duplexer

Cell PA								Rx Front End IC

PCS PA

VCO

PCS Tx filter

AMPS IF Xtal filter

Cell Tx filter

CDMA IF Saw filter

VCTCXO

TX IC

Rx Back End IC

Synthesizer IC

FM Radio section

D2800 UEM

Memory

Bluetooth section

Figure 2: PWB components - top

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ISSUE 2 - October 2006

					2865/2865i (RM-193)
Nokia Customer Care					RF Description and Troubleshooting

RF connector

Tx I and Q test points

Rx I and Q test points

Figure 3: PWB components - bottom

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2865/2865i (RM-193)

RF Description and Troubleshooting

Preliminary RF Troubleshooting

Verify the following if the mobile terminal cannot make a call:

•The mobile terminal is in Normal or Test Mode (i.e., the mobile terminal is searching for a signal, net server is on).

•The Preferred Roaming List (PRL) is loaded into the mobile terminal (for Normal mode).

•The mobile terminal is tuned and has passed tuning. Read the tuning parameters using the Read Parameters component in Phoenix. An untuned mobile terminal has all zeros in the tuning file.

•The call box channel is set for a channel in PRL.

•The SID is correct and entered into the mobile terminal. For Test mode, SID is 4 and paging channel is: 385/Cell and 1175/PCS.

•The VCTCXO is centered properly within tuning limits as described in the "VCTCXO Manual Tuning" section on page 49.

•The transmitter and receiver are working properly in Local mode. See "Transmitter RF Troubleshooting" on page 9 and "Receiver RF Troubleshooting" on page 24 for detailed information.

RF Troubleshooting Equipment List

You will need the following equipment for RF troubleshooting:

•Computer with AMS version of Phoenix

•Agilent 8960 CDMA call box (or equivalent)

•Signal Generator

•Power Supply

•Digital Multimeter

•Diagnostic Test Jig

•Spectrum Analyzer

•AMS RF Probe, AAS-10A (p/n0730306) or AAS-10B (p/n0730307)

•Oscilloscope

•RF Connectors and cables

•High Impedance Probe (optional)

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Transmitter RF Troubleshooting

Transmitter Block Diagram

Following is the block diagram for the Tx RF system.

Figure 4: Transmitter system block diagram

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2865/2865i (RM-193)

RF Description and Troubleshooting

Nokia Customer Care

Transmitter Schematics

The following schematics are for general reference only. See the Schematics chapter for detailed versions.

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Company Confidential

ISSUE 2 - October 2006

2865/2865i (RM-193)

Nokia Customer Care

RF Description and Troubleshooting

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2865/2865i (RM-193)

RF Description and Troubleshooting

Transmitter Troubleshooting Guidelines

Use some of the following guidelines when as you are troubleshooting.

•Always perform visual inspection of PCB under microscope to check proper placement, rotation, and soldering of components.

•Look for presence of well-defined CDMA modulated signal on spectrum analyzer at correct frequency. If signal is present but off frequency or shape looks distorted, check synthesizer. Possibly, one of the synthesizers is not locked, or VCO has no output signal. Check the synthesizers for proper frequency and amplitude. See "Tx Output Spectrum" on page 21 and "Synthesizer Troubleshooting" on page 43.

•Check that power supplies to transmitter have correct voltage. See "Tx RF Component Diagram" on page 22.

•If signal is very low in amplitude, check the probing diagram to determine what part of TX chain is ‘broken’. See "DC Test Points" on page 23.

•Check that AGC PDMs produce and adjust TX power within the proper limits. See Figure 9 on page 15, Figure 12 on page 17, and Figure 13 on page 19.

Transmitter Troubleshooting Setup

Use the following sets of procedures to troubleshoot the transmitter using Phoenix (AMS). Due to the compact layout of the mobile terminal, some of the major test points are not accessible without destroying the shield frames. For example, duplexers/diplexer/ couplers test points are blocked by the test jig, the PA test points are underneath the shield frame, etc.

Perform this check in the following order:

1.Tx power at the RF connector.

2.All Tx DC points.

3.All soldering jig points for the whole Tx chain.

4.UHF LO presence:

•If the UHF LO is present, check the N7000 output.

•If the UHF LO is not present, it is a synthesizer problem.

5.If there is no N7000 output:

a.Change the N7000.

b.If the problem persists, reflow the duplexers, diplexer, and couplers.

c.If the problem persists, change the PA.

6.If there are several failed mobile terminals with the same symptoms, it may be necessary to break one to determine the cause.

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ISSUE 2 - October 2006

					2865/2865i (RM-193)
Nokia Customer Care					RF Description and Troubleshooting

Use the following sections to set up troubleshooting in Phoenix according to the band you are using:

•"AMPS Tx Setup" on page 13

•"Cell Tx Setup" on page 15

•"PCS Setup" on page 17

AMPS Tx Setup

Use the following procedures to prepare for AMPS Tx troubleshooting using Phoenix.

Note the 6236i variant does not support AMPS.

1.Connect the RF test connector to a spectrum analyzer.

2.Connect the mobile terminal to the PC via a test jig. (The bottom connector is a USB port.)

3.Connect a power supply to the mobile terminal.

4.Open the Troubleshooting menu, and click Phone Control. The Phone Control dialog box appears.

5.Click the LOCAL button in the Phone State tab to put the mobile terminal into Local Mode.

Figure 7: Phone Control dialog box

6. Open the Troubleshooting menu, point to AMPS, and click AMPS Control.

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RF Description and Troubleshooting

The AMPS Control dialog box appears.

Figure 8: AMPS Control dialog box

7.Click the Tx Control tab.

8.In the Set Channel field, type 384 and Power Level field, type 5.

9.Select the Transmitter ON and Use DSP 2 codes options.

10.Click Execute.

11.Configure the spectrum analyzer using the following values:

•Center Frequency = 836.52 MHz

•Span = 100 MHz

•Amplitude = 20 dBm

•Attenuation = Auto

•BW = Auto

Table 1: RF PDM Values at Power Level 5

	Description/Field		Reference Value
	AGC1		-59
	AGC2		-512
	PA Gain		-200
	Rx IF AGC		+179
	AFC		-12
	Pout		+17dBm
	Current		370mA
	Pout w/AAS-10 at Ant. Conn.		-8 dBm
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						2865/2865i (RM-193)
Nokia Customer Care						RF Description and Troubleshooting

Figure 9: RF PDM dialog box for AMPS

12. Click Read Phone to update the values.

Cell Tx Setup

Use the following procedures to prepare for Cell Tx troubleshooting using Phoenix.

1.Connect an RF test connector to a call box.

2.Connect the mobile terminal to the PC via a test jig. (The bottom connector is a USB port.)

3.Connect a power supply to the mobile terminal.

4.On the Phone Control dialog box, click the LOCAL button in the Phone State area to put the mobile terminal into Local Mode. (See Figure 7 on page 13.)

5.Open the Troubleshooting menu, point to RF, and click RF Main Mode. The RF Main Mode dialog box appears.

Figure 10: RF Main Mode dialog box for Cell Mode

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RF Description and Troubleshooting

6.Select the following values on the RF Main Mode dialog box:

•Band = Cell (CDMA)

•Channel = 384

•Mode = Rx/Tx

7.Click Set.

Note: Be sure that the “RF Main Mode set successfully” message appears in the status bar.

8.Open the Troubleshooting menu, point to RF, and click CDMA Control. The CDMA Control dialog box appears.

Do NOT select this option

Figure 11: CDMA Control dialog box for Cell Tx troubleshooting

9.Select the following values:

•State = Rho ON

•Band = Cell

•Radio Configuration = Mode 1: IS-95 Voice

Note: Do NOT select the Set default PDM values option.

10.Click Execute.

11.Configure the spectrum analyzer using the following values:

•Center Frequency = 836.52 MHz

•Span = 100 MHz

•Amplitude = 20 dBm

•Attenuation = Auto

•BW = Auto

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Nokia Customer Care					RF Description and Troubleshooting

	Table 2: RF PDM Values
	Description/Field	Reference Value
	AGC1	0
	AGC2	-512
	PA Gain	+114
	Rx IF AGC	0
	AFC	0
	Pout	+16dBm
	Current	360mA
	Pout w/AAS-10 at Ant. Conn.	-8 dBm

Figure 12: RF PDM Control dialog box for Cell band

12. Click Read Phone to update the values.

PCS Setup

Use the following procedures to prepare for PCS Tx troubleshooting using Phoenix.

1.Connect an RF test connector to a call box.

2.Connect the mobile terminal to the PC via a test jig. (The bottom connector is a USB port.)

3.Connect a power supply to the mobile terminal.

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RF Description and Troubleshooting

4.Open the Troubleshooting menu, and point to Phone Control. The Phone Control dialog box appears. (See Figure 7 on page 13.)

5.Click the LOCAL button in the Phone State area to put the mobile terminal into Local Mode.

6.Open the Troubleshooting menu, point to RF, and click RF Main Mode. The RF Main Mode dialog box appears. (See Figure 10 on page 15.)

7.Select the following values on the RF Main Mode dialog box:

•Band = PCS (CDMA)

•Channel = 600

•Mode = Rx/Tx

8.Click Set.

Note: Be sure that the “RF Main Mode set successfully” message appears in the status bar.

9.Open the Troubleshooting menu, point to RF, and click CDMA Control. The CDMA Control dialog box appears. (See Figure 11 on page 16.)

10.Select the following values on the CDMA Control dialog box.

•State = Rho ON

•Band = PCS

•Radio Configuration = Mode 1: IS-95 Voice

Note: Do NOT select the “Set default PDM values” option.

11.Click Execute.

12.Open the Troubleshooting menu, point to RF, and click PDM Control.

13.Configure the spectrum analyzer using the following values:

•Center Frequency = 1880 MHz

•Span = 100 MHz

•Amplitude = 20 dBm

•Attenuation = Auto

•BW = Auto

	Table 3: RF PDM Values
Description/Field		Reference Value
AGC1		-130
PA_Bias		85

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Nokia Customer Care							RF Description and Troubleshooting
						Table 3: RF PDM Values (Continued)
						Description/Field	Reference Value
						PA_DC_DC	110
						Pout at RF connector	+15dBm
						Current	340mA

Figure 13: RF PDM Control dialog box for PCS band

14. Click Read Phone to update the values.

Transmitter RF Troubleshooting Procedures

After Phoenix is set up using either the AMPS, Cell, or PCS setup procedures, use the following steps to troubleshoot the transmitter.

1.Using a voltmeter, check to see that all VR2, VR6, and VR1B are on the transmit system. (See "Tx RF Component Diagram" on page 22.)

•If any are missing, look for SMD problems around the Tx IC and the UEMEK.

•If SMD is good, replace the UEMEK.

2.Once all DC voltages are present, check the AGC control voltages. (See "AMPS Tx Setup" on page 13, "Cell Tx Setup" on page 15, or "PCS Setup" on page 17.)

•If the voltages are incorrect, check the SMD around TX_AGC1.

•If the SMDs are correct, replace the D2800.

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RF Description and Troubleshooting

3.Using an oscilloscope, check the I and Q input modulation wave forms at test points. See "Tx RF Components of the PWB" on page 22. They should all be present with an AC swing of about 500mVpp, with an offset of +1.2V.

•If one or more waveforms is missing, look for SMD problems around these resistors.

•If the SMD is good, replace the UEMEK.

4.Use an AAS-10 RF probe to probe the Cell Tx output of the Tx IC.

•If there is no RF or low RF, look for a faulty SMD around the Tx IC.

•If the SMD is okay, replace the N7000.

5.Probe the PA input.

•If the level is low, look for an SMD issue on the Tx filter.

•Reflow or replace the filter as necessary.

6.Probe the PA output.

•If the RF is missing or low, look for Vbatt voltages and SMD issues on and around the PA.

•If these are okay, replace the PA.

7.Probe the duplexer output.

•If the RF is missing or low, reflow or replace the duplexer.

8.Probe the coupler output.

•If the RF is missing or low, reflow or replace the coupler.

9.Probe the diplexer output.

•If the RF is missing or low, reflow or replace the diplexer.

Failed Test: Tx PA Detector

Use the following steps if you encounter a failed test for the Tx PA detector:

1.Use Phoenix to set the mobile terminal into Local Mode and activate the Tx with default output power.

2.The output power at the RF test connector should be 15dBm ± 4dB. If not, adjust the PDM values, or troubleshoot per procedure above.

3.Using a voltmeter on DC, probe the detector output at C7315. The voltmeter should read approximately 1.4V. If not, replace N7302.

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					2865/2865i (RM-193)
Nokia Customer Care					RF Description and Troubleshooting

Tx Output Spectrum

Following is the correct output of the mobile terminal on a spectrum analyzer with 100MHz span. Note that if you are using the AAS-10 probe with the mobile terminal connected to the call box, the amplitude should be approximately -7dBm at the antenna test point on the top of the PWB.

Figure 14: Correct output spectrum

Following is an example of incorrect output.

Figure 15: Incorrect output spectrum

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Company Confidential

Page 21

2865/2865i (RM-193)

RF Description and Troubleshooting

Tx RF Component Diagram

Following are the Tx RF components.

Tx IC

PCS Tx SAW Filter PCS PA

PCS

PCS

Duplexer

Diplexer Coupler

Cell			Tx				Cell		PA
SAW Filter

DC	Cell	Cell	Power
Connector	Duplexer	Coupler Detector

Figure 16: Tx RF Components of the PWB

Tx DC Probe Points

Following are the Tx DC probe points of the PWB.

Tx UHF LO

Lock Voltage

VR6:

VR2:

1.2V

2.8V

2.76V

Iref PCS:	VCC_PA:
2.3-2.9V	0-4.6V

Power Detector Output (DCOUT)

AGC 1 & 2

Iref_Cell:

PCS:

Cell:

Pins 16 & 17

~2.4-3.4V

2.0V

@ <5dBm

2.0

V @ <5dBm

0.1 to1.8V

1.7V

@ <15dBm

1.8

V @ <15dBm

1.2V

@ <23dBm

1.4

V @ <23dBm

Tx IQ Test points (need to scrape off solder masks)

Values are ~ 1.2 VDC and ~500mV p-p on the oscilloscope

All 4 test points should be approximately equal.

Figure 17: Tx DC probe points

Page 22

Company Confidential

ISSUE 2 - October 2006

2865/2865i (RM-193)

Nokia Customer Care

RF Description and Troubleshooting

Tx RF Probe points

Figure 18 shows the Tx RF probe points of the PWB.

PCS Frequency 1880 MHz Cell/Amps Frequency 836.25 MHz

Diplexer out

PCS +16dBm

PCS TX IC out

PCS PA in

PCS PA out

PCS Diplexer

Cell +10dBm

-7dBm

-13dBm

+17dBm

out +15dBm

Amps +1dBm

Cell TX IC out -7dBm	Cell PA in -7dBm	Cell PA out +20dBm	Cell Duplexer out	Pwr Detector
Amps -33dBm	Amps -33dBm	Amps -6dBm	+20dBm	PCS -13dBm
			Amps -7 dBm	Cell +4dBm
PDM: PA Gain=-260, AGC2=-230, Cell AGC1=-20, PCS AGC1=-70				Amps +20dBm

Figure 18: Tx RF probe points

DC Test Points

Figure 19 shows the DC test points.

D2800

VIO 1.8V

D2200

VR3 Synth 2.78V

VR5 Rx 2.78V

VR4 Rx 2.78V

VR7 Rx 2.78V

VR6 Tx 2.78V

VR2 Tx 2.78V

Vbatt 3.2-4.7V

VR1B Tx 4.75V

VR1A Synth 4.75V

Figure 19: DC Test Points

ISSUE 2 - October 2006

Company Confidential

Page 23

2865/2865i (RM-193)

RF Description and Troubleshooting

Table 4: RF PDM Values

Description		Supply
VR1A	> 100 Ohms to Gnd	UHF PLL
VR1B	> 100 Ohms to Gnd	Tx IC
VR2	7.5k Ohms to Gnd	Tx IC PA detector
VR3	> 500 Ohms to Gnd	VCTCXO
VR4	4.3k Ohms to Gnd	VCO
VR5	3.2 - 5.1 Ohms to Gnd	Rx FE IC, Rx BE IC
VR6	300 Ohms to Gnd	Tx IC
VR7	~ 500 Ohms to Gnd	Rx BE IC
VIO	> 1M Ohms to Gnd	Rx BE IC

Receiver RF Troubleshooting

The heart of the receiver is the Rx Front-end IC, which contains two LNAs and mixers. The other components are passive. There are two RF SAW filters for the Cell and PCS bands. In addition, there are two IF filters, an IF SAW for CDMA and an IF crystal for AMPS. The back-end of the receiver consists of the RX Back-End IC. VGA and IQ Demodulator are the main function.

Page 24

Company Confidential

ISSUE 2 - October 2006