NOTE! When assembling the screw use
17 Ncm torque.
10.
Remove engine module
11.
Remove microphone
Note: When the phone is disassembled (opened), please be careful NOT to TOUCH the
antenna clip (x703) or the antenna ground clip (x704). During re-assembly, ensure that
the clips are not damaged.
Each main portion of the circuit will be described in enough detail for the troubleshooter
to determine whether or not that part of the circuit being evaluated is functional. It will
be helpful to use the placement diagram, which illustrates all of the necessary testpoints
in the baseband circuit, to troubleshoot the phone. The placement diagram is intended to
be used concurrently with this document. Herein, TPD refers to Test Point Designation.
TP refers to Test Point originating from schematics. Note that the baseband consists of
mainly a few ASICS, and there is very little discrete circuitry other than passive components. Baseband problems are few compared to previous projects with much more discrete circuitry.
Therefore, hardware bugs will not be as obvious since they will likely NOT be a failing
part, but perhaps SMD or mechanical issues.
Main Circuit Sections
Power Circuitry
There are two ASICs in the baseband section, which supply power to most of the phone.
CCONT is the main power management ASIC, and PENTA is used to supply additional
switchable regulators for use in RF. Two discrete linear regulators are used as well.
CCONT
CCONT is the main power management ASIC. Its features include eight 2.8V linear regulators, a linear regulator with adjustable output, a reference voltage output, a 5V switch
mode regulator, an 8 channel A/D converter, and 32kHz clock circuitry. Each of the main
functions and signals is described below, including information on how to verify correct
operation.
Vbat
CCONT is powered directly from the battery voltage, Vbat. Since CCONT is a uBGA, the
physical connection of CCONTs power pins cannot be verified. Vbat must be checked
instead at the closest external component, which is shown as TPD30. Valid voltages are
3.1 – 4.1V and should always be powered, assuming voltage is applied to the battery terminals.
Vref
Vref is used as a reference voltage both internal and external to CCONT. It is switchable
between the nominal voltages of 1.500V and 1.251V, with the default at power up being
1.500V. The phone uses the 1.251V reference, so once flash software is running Vref
must switch to 1.251V.
Check Vref at TPD6. Valid voltages are 1.478 – 1.523V and 1.244 – 1.258V, respectively.
Vbb supplies power to most of the baseband circuitry. This regulator should be on at all
times during CCONTs power on, reset, and sleep modes. Nominal voltage is 2.8V, but
anything in the range 2.7–2.87V is valid. Vbb is found at TPD3.
2. RF Regulators (VR1–VR7)
VR1 through VR7 are referred to as the RF regulators. Most are switchable, and all should
be within 2.67 – 2.85V when they are on (2.8V nomi nal). VR1 and VR6 are always on
during CCONTs power on mode. The rest of the regulators are switchable and are normally on during one or more of the various phone states, but may be turned on at any
time with the service software in order to verify their output. The RF regulators can be
checked at the following test points.
a) VR1 – TPD11
b) VR1_SW – TPD12
c) VR2 – TPD40
d) VR3 – TPD38
e) VR4 – TPD4
f) VR5 – TPD39
g) VR6 – TPD10
h) VR7 – TPD41
i) VR7A –TPD9
3. V2V (VMAD)
The V2V regulator is intended to power the MAD4 ASIC core. The output is adjustable
from 1.3V to 2.65V in 0.225V steps, and is used with MAD4 ver 3 (but not MAD4 ver 2).
The output at V2V, when MAD4 ver 3 is mounted, should be 1.750V ±5% and can be
checked on TPD2.
Switch mode regulator
1. V5V (+5V_POWER)
V5V is a 5V switch mode regulator, which always remains on during CCONT power on
mode. Valid voltages are 4.8V to 5.2V, and it can be checked at TPD16.
2. VSIM (3V_5V)
VSIM is powered by the same switch mode regulator as V5V, however, it is switchable
between 3V and 5V. The phone uses VSIM as the 3V FLASH programming voltage, so it
should remain off unless the phone is being flashed. Valid voltages are 2.8V to 3.2V, and
it can be checked at TPD7 (or TP33 on PWB).
A/D Conversion
CCONT contains a 10–bit A/D converter that is multiplexed between 8 different inputs.
They are used mainly for battery and charger monitoring. The 8 inputs are Vbat (battery
voltage), ICHAR (charger current), VCHAR (charger voltage), BSI (battery type), BTEMP
(battery temperature), VCXOTEMP (PA temperature), RSSI (AMPS receive signal strength),
and EAD (accessory detection). These readings can be accessed through the service software. Check for shorts or opens on the resistor networks connected to these signals if the
flash align test software reports that they are out of range.
Watchdog
CCONTs watchdog circuitry consists of an eight bit down counter that causes CCONT to
power down when zero is reached. The counter may be reset by loading a new, non–zero
value into the watchdog register via CCONTs serial bus. It is difficult to verify the watchdog function, but the serial bus may be verified.
There is a watchdog disable pin which allows the watchdog timer to expire without
shutting down the phone, but this pin is mainly used as one of the methods to turn on
CCONT from power off mode. While the phone power key is pressed, this pin should be
pulled low and can be checked at TPD 35 (R325).
The watchdog can be disabled by pulling down the above mentioned pin(WDDISX) by
installing a 0 Ohm resistor at R307, and removing R325.
Serial bus
Since the serial bus is used to control almost all of CCONTs functions, any shorts or open
circuits on these three lines would cause CCONT to be completely nonfunctional. The
main symptoms are the following:
CCONT will turn on when the power key is pressed (verify this by checking Vbb), but will
then power off after 32 seconds. All three serial bus sig nals (CCONTCSX,
UIF_CCONT_SDIO, and UIF_CCONT_SCLK) should toggle when attempting to write to a
CCONT register.
Note: If the LCD does not come on during this time, however, it may indicate that the
serial bus is functional, but phone does not have valid flash code.
PENTA
PENTA supplies power to the RF section. It has 5 independently switchable regulators
that are controlled via separate enable pins. There is also a common enable pin that must
be active in order to turn on any of the regulators. Each of the regulators, P1–P5, should
have output voltages between 2.7V and 2.85V (2.8V nominal). These can be checked at
the following test points.
There are three regulators used in addition to CCONT and PENTA. One is controlled by
CCONTs VR7 regulator output and used as a low noise power source for RF. This regulator
is 2.8V nominal and can be checked at TPD9.
The second regulator is used to power the data cable accessory, so output is enabled only
when a data cable accessory is detected. This regulator is also 2.8V nominal and can be
checked at TPD51 (shares SGND).
The third regulator is used to power the DSP portion of MAD4. It is enabled by Vbb, and
difference between the rise times of the DSP regulator and Vbb should be less than
200usec. This regulator is 2.8V nominal and can be checked on pin 1, 30, or 115 of the
MAD4 ASIC. (This component is most likely stuffed if MAD4_V3 is used.)
Clocks
Sleep Clock
The 32kHz sleep clock is generated by CCONT, and can be checked at TPD31. The 32kHz
square wave will be present only after the phone is turned on. If no signal is present on
this line, check the output of the oscillator at R304. This signal should be a 2Vpp clipped
signal riding on 1.5V DC.
System Clock
The 19.2MHz system clock is generated by the VCTXO in the RF section, and then squared
in CAFE. Check TPD23, which should be approximately a 0.5V sinewave riding on 1.8V
DC. Check TPD25 (or TP14*), which should be a 2.8V squarewave. This clock is not active
during the phone’s sleep mode (CLK_EN is low during sleep mode).
*Note that TP14 on NSD–3AW has been moved.
CDMA clock
The CDMA clock is 9.8MHz and is generated in CAFE with a PLL. This should be a 2.8V
square wave and can be verified at TPD24 (TP13).
Charging Circuit
The charging switch, CHAPS, is controlled by a PWM from CCCONT. This PWM can be at
1Hz or at 32Hz, with varying duty cycles, and should only be active when a charger is
detected. The frequency should be 1Hz when an ACP–7 is detected and 32Hz when an
ACP–9 is detected. To verify correct operation of CHAPS, monitor the charging current
(ICHAR) with the service software. When the PWM is off, current must be approximately 200uA. When the PWM is on, it must be greater than approximately 300mA.
CAFE
The CAFE ASIC performs various functions with respect to the RF circuitry and audio. It
digitizes the analog voice signals from the microphone as well as converts received digital data to voice signals to be sent to the earpiece. This also includes accessory microphones and speakers. It also generates and decodes I and Q data for CDMA, and
demodulates FM (AMPS) signals. CAFE also acts as a clock squaring circuit and CDMA
clock generator.
Microphones
The internal microphone is biased using transistor V201, which is powered by VR1_SW
(TPD12, 2.75VDC). Check also the output of V201. V201, R220 and C212 should be
installed, and R202 should not be installed. MICP must be about 1.7VDC, and MICN must
be about 0.4VDC. Internal microphone bias is active only during a call. The XMIC is
biased by the AUXOUT signal (pin 75) through R209 and R208. The output voltage at pin
75 is about 1.5V.
Earpiece and XEAR
The internal earpiece is driven differentially from pins 77 and 80 (EARP and EARN). The
DC voltage on these two pins is 1.35V. The difference in the DC voltage between these
two pins must not be more than 50mV.
The XEAR signal drives audio to the external accessories. The CAFE signal name is HF (pin
81). The DC level on this pin should be 1.35V. HFCM (pin 82) should also be at 1.35V. The
difference in DC voltage between these two pins should not be more than 50mV.
Note that SGND is the return path for XMIC and XEAR.
Clock circuit
A 19.2MHz sinusoid should appear on pin 25 (Also TPD23). This is from the VCTCXO in
the RF. The CAFE will then produce a 19.2MHz clock at pin 18 (TPD25), and a 9.83MHz
clock on pin 19 (TPD24). See also Clocks section.
AMPSMOD
AMPSMOD is the voice signal to modulate (FM) the RF carrier for transmission. It is the
voice signal that has been processed by the DSP(MAD4) for transmission in AMPS mode.
It represents a modified version of the signal produced by the microphone (CAFÉ pin 58).
Transmit and Receive RF Signals
In CDMA mode, receive I and Q channel RF signals [RXIQ(3:0)] come into CAFÉ at pins 44,
45, 47, and 48. C207, C208, C209, and C210 can also be checked for these signals since
they are in series with the CAFÉ pins. Transmit I and Q RF signals [TXIQ(3:0)] can be seen
at pins 55, 56, 59, and 60 and C201, C204, C222, and C224.
In AMPS mode, the modulated receive RF signals (LIM_P and LIM_N) can be seen coming
into pins 23 and 24 and C216 and C217. For the AMPS Transmit signal, see AMPSMOD
above.
Both the TX and RX paths are also described in section Audio Failures.
MAD4
The MAD4 ASIC is the core of the baseband functionality and basically contains the DSP,
MCU, and CDMA logic. The DSP is used to perform functions such as RF control, DTMF
tone generation, and it implements the vocoder. The MCU is used to perform functions
that do not require as much power. These are higher level functions such as UI software
(key presses, backlighting, LCD functions, etc.) and mode control.
DSP
The DSP sends control signals to the RF via PDMs. In order to control RF parameters such
as TX_VCO_CAL or TX_LIM_ADJUST, a continuously variable analog signal must be used.
Since the DSP outputs only digital signals, a PDM RC circuit is used to convert the digital
output signal to an average analog voltage. A PDM line will always have a series resistor
followed by a shunt capacitor. The output of the MAD4 PDM lines will appear as squarewave signals. However, after the shunt capacitor the signals will appear to be DC with
perhaps a slight ripple. The RC circuit acts as an integrator in order to yield the average
value (DC) of the squarewave signal.
The transmit data bus (TXD(7:0)) is 8 bits wide. In CDMA this bus is multiplexed between
sending I and Q data. The signals required to transfer TX data are TXGATE, CLK9M80, and
IQSEL. TXGATE must be high to transfer data, and the data is clocked by CLK9M80, which
is running at 9.8MHz. In AMPS mode, CLK9M80 is running at 120kHz, therefore, data is
being transferred from MAD4 to CAFE at 120kHz.
The JTAG lines are intended to be used to operate the DSP (and/or MCU) externally.
External Regulator
A separate 2.8V external regulator powers the Lead (DSP) independently. Eventually, the
next version of MAD4 will be used and the Lead may be powered by VMAD from CCONT.
See External Regulators section under CCONT/Linear Regulators. Note: This regulator is
also mentioned in section Power Circuitry.
Note: this regulator may not be present on any HW that uses MAD4_V3.
MCU
The MCU is used to perform functions that require less processing power than the DSP. It
runs UI software, mode control, interfaces to MBUS, downloads code to flash, reads and
writes the EEPROM, controls charging, and interprets A/D data from CCONT. (Used only
in NSD–3AW [and NDS–1AW] NBA chip is used in synchronization between MAD4 and
SRAM.)
MAD4 interfaces to three memories — Flash, SRAM, and EEPROM. All of them are powered by 2.8V (Vbb). During Flash programming, Vpp (signal name is Vff on schematic) is
driven with 3V at the PC flash stations.
Problems
Phone won’t power up
Do a visual inspection. Verify that all parts are on the board correctly, and that none is
missing.
Check that the 32kHz clock turns on when attempting to power up.
Check the power circuitry. This includes VBAT, Vref, and all of the linear regulators, as
well as the Penta regulators. Verify also that the external regulator that powers MAD4
(LEADVCC) is functional – if present.
Flash Align
Test 9
High current: This indicates that the problem is likely caused by a shorted component.
Check orientation of major components (including RF), and check for shorts. Likely components are those that are powered directly from Vbat such as CCONT, the PAs, and various capacitors.
Low current: This indicates that CCONT is not powering on. Verify CCONT circuitry.
Test 10
Flash: Failure to flash is the main baseband failure. Check all the CCONT regulators,
especially Vbb, VR1, and VR6 for shorts. Check clocks and reset circuitry. Check for shorts
on the address, data, and chip enable lines on the memories and MAD4. If a short is
detected, it may be that it is beneath the BGA flash and may have to be replaced.
NOTE: There is no ROM software that can be run when the phone does not flash. Therefore, it must be visually (or by Ohmmeter) determined whether there is an eventual short
between two or more of the address or data lines.
In the field
Cracked or broken solder may cause failures to occur. Reflowing some of the major components may fix problems in case the phone is functioning errantly (some buttons may
not work, the phone may not ring, etc.) or may not power on anymore.
Battery will not charge
If the battery won’t charge (phone won’t allow the battery to charge), check CHAPS and
the charging circuit. It may also be necessary to verify the A/D functionality of CCONT
since this is the method of detecting battery type, charger type, etc.
If audio fails to be heard from the earpiece (or XEAR), check the following:
Check earpiece contacts.
Verify that the CAFÉ EARP and EARN bias is on. If necessary, check the entire receive
path—Rx voice data comes from the RF through the RXIQ bus (CDMA) or LIM_P and
LIM_N (AMPS), then to MAD4 through RXD (11:0) (Refer to schematic). See the Baseband
section of the Service Manual for more detail on RXD bus usage.
The Rx voice data then goes back to CAFE on CAFESIO (0), and then to the earpiece or
XEAR. CAFESIO (2) must also be active.
Conversely, if the transmit audio is not working, the fault could be anywhere in the
transmit path. Check the following:
Check microphone contacts.
Microphone bias.
Tx voice data is transferred from CAFÉ to MAD4 on CAFESIO (1). CAFE-SIO (2) must also
be active. Tx voice data is then sent back to CAFÉ on the TXD bus (See schematic). See
the Baseband section of the Service Manual for more detail on RXD bus usage.
Tx voice data is then sent to RF on the TXIQ bus (CDMA) or AMPSMOD (AMPS).
Test points (TPD) are illustrated in the schematic diagrams.
RF Troubleshooting
This document is written for use in conjunction with the WinTesla Tuning and Testing
software. Screen shots of the menu structures are shown throughout the document. This
document should be used in conjunction with the phone’s schematics which are referred
to in detail throughout.
WinTesla has three key menus:
Configure — Basic set up covered in WinTesla General Set Up
Testing — This menu allows switching on the phone in different modes
Tuning — This menu allows tuning and storing of data to eeprom
Tuning is described in four parts:
A description of the tuning: Describes the tuning process
Definition of result: What tuning is storing to eeprom
Manual Verification: How to use WinTesla to tune the phone
Troubleshooting: Outlines key components to be checked
WinTesla General Set Up
Connect the phone to the PC COM port and start WinTesla. Select “Product” and “New”
and the phone configuration will be selected automatically.
Select “Configure” and “Frequency Plan”. You will then be able to see and also change
the default AMPS and CDMA Channels. The cable loss should also be entered here.
Note: It is possible to enter a Tx and Rx cable loss separately; however if a single cable is
being used, then both losses should be the same. Also the loss will be different for the
1900MHz band and the 800MHz band: hence, sections for both.
Testing Menu
AMPS Fault Finding Setup
For all AMPS transmitter and receiver testing and troubleshooting select “Testing” and
then “AMPS/Baseband Tuning”. This automatically sets the receiver on and the transmitter on Channel 380 Power level 3.
The transmitter power level can be set by selecting the “Power Level”. The TX_LIM_ADJ
and other PDMs can be adjusted by selecting “PDM Ctrl”.
Cell Band CDMA Fault Finding Setup
Both 1900MHz and 800MHz CDMA are started from the same selection of “Testing” and
“CDMA”. Entering this screen switches on both the transmitter and receiver on Channel
364. For PCS, simply click the PCS box. The PDMs can be adjusted with the slider or by
entering a value. The transmitter is switched off by clicking the “Tx Off” Box. The
RX_IF_AGC is read by clicking the “Read” button. The LNA defaults to ON and OFF can be
switch by ticking the “LNA” box.
Use the same Testing menu as Cell CDMA, once in the CDMA Testing Window click PCS
in the top left hand corner. See previous section.
Tuning Menu
The tuning menu is divided into the following sections:
Battery
AMPS
800 CDMA
1900 PCS
In all the tunings WinTesla will prompt you with the equipment settings. At the end of
the tuning WinTesla will give you the option to save the new tuning values to EEPROM or
to exit without saving new values to EE-PROM.
This test tunes the VCTCXO to exactly 19.2 MHz using a DC voltage (TP100) controlled by
the AFC PDM. The resulting PDM is stored to eeprom.
The unmodulated AMPS transmitter is set on Channel. The output carrier is monitored
with a spectrum analyzer. Click on WinTesla Help for equipment set up. The AFC PDM is
tuned until the RF carrier frequency is within ±250Hz of 841.5MHz (i.e. Channel 550).
The AFC must be tuned if the VCTCXO is replaced.
On SSP phones where there is no AMPS, the PCS transmitter is used; however, the CDMA
IQ modulation is switched off and the AFC is tuned on the CW carrier.
NOTE: The Spectrum Analyzer must be connected to a high stability 10MHz reference at
the rear of the instrument. If this is not done, then the tuning will not be accurate.
Definition of Result
The result of this tuning is the AFC PDM stored to eeprom which puts the VCTCXO at the
correct frequency.
The VCTCXO reference designator is G501. VR1 is supplies 2.7v to the VCTCXO (TP101)
through R501 and decoupled with C561. The VCTCXO is controlled by a DC level from the
AFC PDM in MAD connected to Pin 132. The PDM is filtered by R114 and C130 in the
base band section and by R504 and C507 in the RF section. Resistors R503 and R538
center the PDM voltage. Typically a correctly tuned VCTCXO should have approximately
2 volts on pin 1 (TP100).
Adjustment of the AFC PDM from 0 to 511 should result in a voltage change on G501 Pin
1 (TP100) between 1.9 and 2.2 volts with a 10KHz change in the transmitter output frequency in Cel or a 22KHz change in PCS.
On SSP phones which do not have AMPS, clicking the “PCS AFC Tuning On” box will disable the CDMA modulation allowing AFC tuning to be performed on the RF carrier feed
through.
19.2MHz measured at the output of the VCTCXO Buffer (TP102) with a 10 Mohm probe.
AMPS Tuning Tx Power Levels
Description of Test
These tests tune all the AMPS power levels 2 to 7 to the required output power level by
changing the TX_LIM_ADJ PDM (TP103). This is done with the phone in AMPS mode with
transmitter on and the TX_RF_AGC PDM set to FF and TX_IF_AGC set to 1FF.
NOTE: The AMPS Transmitter band is frequency compensated with fixed values, these
are referenced to the channel with the lowest loss which is Channel 550. It is very
important to tune the transmitter using Channel 550; otherwise, the maximum allowable power may be exceeded.
If only the top PL2 or PL3 power levels fail then the transmitter is slightly short of gain.
This could be caused by many transmitter faults. Check the PA N605 output Pins
11,12,13,14 (TP104) are not shorted to ground.
Note: This should be done with the phone switched off. If these pins (TP104) are shorted
the PA must be replaced, and it is likely that inductor L618 will have burnt out and
become open circuit. Also check that the Tx VHF LO (TP105) and UHF LO (TP106) are
present at the correct frequency and level (see below).
Tx VHF LO Measured at TIF N604 Pin 3 (TP105) with a Hi Z Probe:
UHF Cel LO measured at Odyssey N703 Pin 2 (TP106) with Hi Z probe when set to Channel 384:
Check the following components in the Tx VHF VCO to see if they are damaged V501,
V504, V508, V511 and L504.
NOTE: If any of these components are replaced, then the Tx Modulation Index must be
retuned.
AMPS Tuning RSSI
Description of Test
Changing the AMPS receiver input level results in different Gains in the Limiting amplifier in RIF to produce a limited output. This test measures AMPS RSSI with high receiver
input signal and low receiver input signal, and then stores these values to eeprom. WinTesla will prompt with what level to set going into the receiver.
Definition of Result
The reported result is the ADC value from CCONT. For RSSI Lo the result should be
between 570 and 970 and is stored to eeprom under the handle
RF_TUNE_AMPS_RSSI_LO_HANDLE. For RSSI Hi result should be between 750 and 1050
and is stored to eeprom under the handle RF_TUNE_AMPS_RSSI_HI_HANDLE.
Manual Verification
Use WinTesla as follows:
Troubleshooting
Check components in the AMPS receiver chain starting with the Duplexer Z701, Down
Converter IC N703, 128.55MHz IF SAW filter Z702, 450KHz Ceramic filters Z706 and
Z708 and RIF N702. Check the Rx VHF LO RIF N702 Pin 20 (TP107) see below. Also check
RIF 450KHz output LIM_P Measured at RIF Pin 17 (TP108) and the RSSI voltage at RIF
N702 Pin 16 (TP109) which indicates the signal level into the receiver.
RSSI Voltage at RIF N702 Pin 16 (TP109) versus Rx Power at RF connector:
AMPS Tuning Rx Audio Gain
Description of Test
This test tunes the DSP Gain so that an RF input signal with 2.9KHz deviation and 1KHz
modulation results in a voltage at the receiver output of 57.4 +/–3 mV RMS. The DSP
Gain is then stored to eeprom.
Definition of Result
The stored eeprom value will result in 57.4mV RMS at XEAR when using JBA4 and receiving an RF signal with 1KHz tone and 2.9KHz deviation.
Verify that the signal on RIF N702 Pin 17 (TP108) shown in the plot above is present on
CAFÉ Pin 24 (TP110). If this is the case then check the test set up.
800 CDMA Tuning Tx IF AGC
Description of Test
The RIF and TIF AGC is approximately a second order curve. This curve is split into 16 segments for both Transmitter and Receiver. Offset and slope values are stored in eeprom for
each of these 16 segments. The offset for the segments is computed from the 3–point
calibration performed in this test. After test a 2
Offset and Slope computed. TX_IF_AGC must be adjusted to achieve the correct power
level for Point 1, when this is done the process must be repeated for Points 2 and 3.
Definition of Result
The results of the 3 point tuning are the 16 slope and offset values, which are stored to
eeprom RF_TUNE_CELL_TX_AGC_OFF-SET_ SLOPE_HANDLE.
If this tuning fails, it is probably the highest power level indicating that there is a gain
loss in the transmitter path. This could be caused by many transmitter faults. Check the
PA N605 output Pins 11,12,13,14 (TP104) are not shorted to ground. Note this should be
done with the phone switched off. If these pins are shorted the PA must be replaced, and
it is likely that inductor L618 will have burnt out. Also check that the Tx VHF LO (TP105)
and UHF LO (TP106) are present at the correct frequency and level (see the AMPS Tuning
Tx Power Levels section).
NOTE: If any of these components are damaged and are replaced then the Tx IF AGC
must be retuned.
Tx Output spectrum at RF Connector with 30dB attenuator on Spectrum Analyzer:
Tx Output spectrum at RF Connector with 30dB attenuator on Spectrum Analyzer:
800 CDMA Tuning LNA Switch
Description of Test
In this test the phone is set to continuous receive mode, a CW signal is put into the
receiver via the RF connector. WinTesla indicates the amplitude. There is a frequency offset of 300KHz from the center of the receiver. The RX_IF_AGC is adjusted by the phone’s
software to make the best use of the CAFÉ ADC. The setting of RX_IF_AGC is then read
from the phone. The LNA is switched from High Gain mode to Low Gain Mode. The
RX_IF_AGC is allowed to readjust itself to again make the best use of the CAFÉ ADC and
the RX_IF_AGC is read a second time. The result is the Gain delta between High Gain and
The displayed result is the High Gain – Low Gain delta in dB after applying the PDM difference to the previously computed 3–point curve fit. This delta should be between
21 and 24dB. This is stored to eeprom handle RF_TUNE_RX_GS_HANDLE.
Manual Verification
Use WinTesla as follows:
Troubleshooting
Check that the RX_GS line on the up–converter N703 Pin 15 (TP111) is changing from
high to low. If this is and the Gain does not change significantly, then the Up–converter
IC N703 is probably faulty and should be replaced.
800 CDMA Tuning Rx IF AGC
Description of Test
The RIF and TIF AGC is approximately a second order curve. This curve is split into 16 segments for both Transmitter and Receiver. Offset and slope values are stored in eeprom for
each of these 16 segments. The offset for the segments are computed from the 3–point
calibration performed in this test. After test a 2
Offset and Slope are computed.
This tuning is done by putting signal level 1 into the receiver, the RX_IF_AGC will then
automatically adjust for max CAFÉ input and the RX_IF_AGC is noted. This process is
then repeated for signal levels 2 and 3.
Definition of Result
The results of the 3 point tuning are the 16 slope and offset values, which are stored to
eeprom RF_TUNE_CELL_RX_AGC_OFF-SET_ SLOPE_HANDLE.
Manual Verification
Use WinTesla as follows:
Troubleshooting
Check components in the 800 MHz receiver chain, from the Duplexer N701, Down converter N703, the 128.1MHz CDMA IF SAW filter Z704 and RFI N702. Check that the
RX_IF_AGC RIF Pin 7 (TP112) changes as the receiver input signal level is adjusted.
NOTE: If any of these components are damaged and are replaced then the Rx IF AGC
second order curve must be retuned.
In this tuning the receiver is calibrated at five different frequencies across the band.
WinTesla instructs the Signal Generator to be set at five specific frequencies and a fixed
amplitude. The RX_IF_AGC is adjusted by the phones software to make the best use of
the CAFÉ ADC. The setting of RX_IF_AGC is then read from the phone at each of the five
frequencies.
Definition of Result
The five different values of RX_IF_AGC are stored to EEPROM.
The RIF and TIF AGC is approximately a second order curve, this curve is split into 16 segments for both Transmitter and Receiver, Offset and slope values are stored in eeprom for
each of these 16 segments. The offset for the segments are computed from the 3–point
calibration performed in this test, then a 2
and Slope computed. TX_IF_AGC must be adjusted to achieve the correct power level for
Point 1, when this is done the process must be repeated for Points 2 and 3.
Definition of Result
The results of the 3 point tuning are the 16 slope and offset values, which are stored to
eeprom RF_TUNE_PCS_TX_AGC_OFFSET_SLOPE_HANDLE.
Manual Verification
Use WinTesla as follows:
nd
order approximation is made and the Offset
Troubleshooting
If this tuning fails it is probably the highest power level indicating that there is a gain
loss in the transmitter path. This could be caused by many transmitter faults. Check the
PA N606 output Pins 11,12,13 and 14 (TP113) are not shorted to ground. If this is the
case PA must be replaced.
Also it is likely that inductor L611 has burnt out and has open circuit. Check the switch to
the split band filter N609 and its control transistor V614 and control line FILT_SEL
(TP114). Check also the Up Converter, N601 and also TIF, N604. Also check that the Tx
VHF LO (TP105) and UHF LO (TP115) are present at the correct frequency and level.
NOTE: If any of these components are damaged and are replaced, then the Tx IF AGC
must be retuned.
1900 CDMA Tuning LNA Switch
Description of Test
In this test the phone is set to continuous receive mode, a CW signal is put into the
receiver via the RF connector with amplitude of dBm and offset 300KHz from the center
of the receiver. The RX_IF_AGC adjusts to make the best use of the CAFÉ ADC. The setting of RX_IF_AGC is then read from the phone. The LNA is switched from High Gain
mode to Low Gain Mode. The RX_IF_AGC is allowed to readjust itself to again make the
best use of the CAFÉ ADC and the RX_IF_AGC is read a second time. The result is the
Gain delta between High Gain and Low Gain modes.
Definition of Result
The displayed result is the High Gain – Low Gain delta in dB after applying the PDM difference to the previously computed 3–point curve fit. This delta should be between 21
and 30dB. It is stored to eeprom handle RF_TUNE_RX_GS_HANDLE.
In the PCS band the RX_GS input to the up–converter N01 is NOT used. Instead the
external LNA is switched on and off with Penta N303 Pin 9 (output P5) (TP116). Check
that the external LNA is being switched on and off by probing. If this is the case then
there is probably a fault with the external LNA. Check the transistor V705 and its collector components L710. Also check the bias circuitry V704 and L708.
NOTE: If any of these components are damaged and are replaced, then the Rx IF AGC
must be retuned.
1900 CDMA Tuning Rx IF AGC
Description of Test
The RIF and TIF AGC is approximately a second order curve. This curve is split into 16 segments for both Transmitter and Receiver. Offset and slope values are stored in eeprom for
each of these 16 segments. The offset for the segments are computed from the 3–point
calibration performed in this test, then a 2
and Slope computed. This tuning is done by putting signal level 1 into the receiver, the
RX_IF_AGC will then automatically adjust for max CAFÉ input and the RX_IF_AGC is
noted. This process is then repeated for signal levels 2 and 3.
nd
order approximation is made and the Offset
Definition of Result
The results of the three point tuning are the 16 slope and offset values which are stored
to eeprom RF_TUNE_PCS_RX_AGC_OFF-SET_ SLOPE_HANDLE.
Check components in the 1900 MHz receiver chain, from the Duplexer N711, External
LNA V705, Down converter N701, the 128.1MHz CDMA IF SAW filter Z704 and RFI N702.
Check that the RX_IF_AGC RIF Pin 7 (TP112) changes as the receiver input signal level is
adjusted.
NOTE: If any of these components are damaged and are replaced, then the Rx IF AGC
must be retuned.
1900 CDMA Tuning Rx IF Compensation
Description of Test
In this tuning the receiver is calibrated at six different frequencies across the band. WinTesla instructs the Signal Generator to be set at six specific frequencies and a fixed
amplitude. The RX_IF_AGC is adjusted by the phones software to make the best use of
the CAFÉ ADC. The setting of RX_IF_AGC is then read from the phone at each of the six
frequencies.
Definition of Result
The five different values of RX_IF_AGC are stored to EEPROM.