Nokia 6255 Service Manual 09rm19bb

Nokia Customer Care

6255/6255i6256/6256i (RM-19)

Mobile Terminal

Baseband Description and

Troubleshooting

Issue 2 05/2005 Company Confidential ©2005 Nokia Corporation

6255/6255i6256/6256i (RM-19)
Baseband Description and Troubleshooting Nokia Customer Care

Contents Page

Introduction ..................................................................................................................................................... 4

Power Up and Reset ....................................................................................................................................6

Power Up - Power Key............................................................................................................................. 8

Power Up - Charger Connection .......................................................................................................... 8

Power Up - RTC Alarm............................................................................................................................. 9

Power Off .......................................................................................................................................................9

Power Consumption and Operation Modes .........................................................................................9

Power-off Mode........................................................................................................................................ 9

Sleep Mode.............................................................................................................................................. 10

Active Mode ............................................................................................................................................ 10

Charging Mode....................................................................................................................................... 10

Power Distribution ....................................................................................................................................11

Clock Distribution ......................................................................................................................................13

RFClk (19.2MHz Analog)...................................................................................................................... 13

RFConvClk (19.2MHz Digital)............................................................................................................. 14

CBUSClk Interface ................................................................................................................................. 15

DBUS Clk Interface................................................................................................................................ 16

SleepCLK (Digital) .................................................................................................................................. 17

SleepCLK (Analog).................................................................................................................................. 18

Flash Programming ...................................................................................................................................18

Connections to Baseband.................................................................................................................... 18

Baseband Power Up .............................................................................................................................. 18

Flash Programming Indication........................................................................................................... 19

Flashing..................................................................................................................................................... 19

Flash Programming Error Codes ........................................................................................................ 22

Charging Operation ...................................................................................................................................24

Battery ...................................................................................................................................................... 24

Charging Circuitry ................................................................................................................................. 24

Charger Detection.................................................................................................................................. 25

Audio .............................................................................................................................................................25

Displays and Keymat ................................................................................................................................25

Main Display............................................................................................................................................ 26

Secondary Display.................................................................................................................................. 27

Keymat...................................................................................................................................................... 27

Camera .........................................................................................................................................................27

DC Measurements.................................................................................................................................. 28

AC Measurements.................................................................................................................................. 28

FM Radio ......................................................................................................................................................29

FM Radio Test ......................................................................................................................................... 29

USB Interface ..............................................................................................................................................31

Accessories ..................................................................................................................................................33

Charging.......................................................................................................................

Pop-port Headset Detection............................................................................................................... 36

FBus Detection........................................................................................................................................ 36

Accessory Detection Through ACI..................................................................................................... 37

RUIM (SIM CAR) ........................................................................................................................................39

Main Display Test Points ........................................................................................................................... 40

............................ 34

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Secondary Display Test Points.................................................................................................................. 45

GPS Module .................................................................................................................................................48

Troubleshooting............................................................................................................................................ 49

Mobile Terminal is Totally Dead ............................................................................................................50

Flash Programming Does Not Work .....................................................................................................51

Power Does Not Stay on or the Mobile Terminal is Jammed ........................................................53

Charger Faults ............................................................................................................................................55

Audio Faults ................................................................................................................................................56

Earpiece .................................................................................................................................................... 56

Microphone ............................................................................................................................................. 57

IHF.............................................................................................................................................................. 58

Vibra .......................................................................................................................................................... 59

Display Faults ..............................................................................................................................................60

Main Display............................................................................................................................................ 60

Secondary Display.................................................................................................................................. 62

Keypad Faults .............................................................................................................................................63

Power Key ................................................................................................................................................ 63

UI Modules............................................................................................................................................... 64

EL Panel and Driver ............................................................................................................................... 65

USB ................................................................................................................................................................66

MMC ..............................................................................................................................................................70

FM Radio ......................................................................................................................................................71

Camera .........................................................................................................................................................73

Bluetooth .....................................................................................................................................................73

SIM ................................................................................................................................................................73

GPS ................................................................................................................................................................75

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Introduction

The 6255/6255i/6256/6256i baseband module is a tri-mode, Code Division Multiple
Access (CDMA), dual-band engine and is based on the DCT4.5 standard. The baseband
engine includes two major Application Specific Integrated Circuits (ASICs):

• D2200 — Universal Energy Management Enhanced Integrated Circuit (UEME IC),
which includes the audio circuits, charge control, and voltage regulators

• D2800 — Main phone processor, which includes system logic for CDMA, two
Digital Signal Processors (DSPs), the Main Control Unit (MCU), and the memory

The BL-6C Li-ion battery is used as the main power source and has a nominal capacity of
1070 mA/h.

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Battery

UHS Jack

DC Jack

Tomahawk

Antenna

Bluetooth

GPS

FM Radio

Zocus

Nut

USB

CBUS

PCM / UART

UART

19.2 MHz

VIO

Production
Test IF

UEME

RF

Tiku EDGE

Sim

Regulation

Charge Control

Audio

FBUS / MBUS

SIM I/F

RTC

D
B
U
S

MCU ARM925

PDRAM

MMC

32 KHz

Amplifier

PWM

PWM

Parallel

Serial

Regulator

Mic

IHF Speaker

EarPiece

Vibra

Disp BL’s

Cam Flash

Int Display

Ext Display

Flash Memory
(Program,
NOR)

SDRAM

Flash Memory
(User, NAND)

VCORE
SMPS

C-DSP Lead3

A-DSP Lead 3

2G System Logic

Figure 1: Baseband block diagram

Keyboard

EL

Camera

IRDA

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Power Up and Reset

The UEME ASIC controls the power up and resets. The baseband can be powered up in
the following ways:

• Pressing the Power button, which means grounding the PWRONX pin of the
UEME

• Connecting the charger to the charger input

• Initiating the Real-time Clock (RTC) alarm, when the RTC logic has been
programmed to give an alarm

After receiving one of the above signals (see Figure 2), the UEME counts a 20ms delay
and then enters reset mode. The watchdog and VCORE start, and if the battery voltage
(VBAT) is greater than Vcoff+, a 200ms delay is started to allow references to settle.
After this delay elapses, the VFLASH1 regulator is enabled. Then, 500us later, VR3, VANA,
and VIO are enabled. Finally, the Power Up Reset (PURX) line is held low for 20ms. This
reset (PURX) is fed to the baseband D2800 processor ASIC, which in turn generates resets
for the MCU and the DSP. During this reset phase, the UEME forces the Voltage
Controlled Temperature Controlled Oscillator (VCTCXO) regulator on regardless of the
status of the sleep control input signal to the UEME.

The FLSRSTx from the UEME is used to reset the flash during power up and to put the
flash in power down during sleep mode. All baseband regulators are switched on when
the UEME is powered on.

The UEME internal watchdogs are running during the UEME reset state, with the longest
watchdog time selected. If the watchdog expires, the UEME returns to the power off
state. The UEME watchdogs are internally acknowledged at the rising edge of the PURX
signal to always give the same watchdog response time to the MCU.

The following timing diagram represents the UEME start-up sequence from reset to
power-on mode.

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Reference signal

PwrOnX

Charger Detection

RTC

UEMRSTX

VCORE

VFlash1

VIO

VANA

VR3

19.2MHz Clk

PURX

Reset mode is entered and
the watchdog starts

End of settling time (only if Vbat > Vcoff+_);
VFLASH1 regulator enabled

VR3, VANA, VIO, and VCORE enabled;
PURX held LOW

D2800 processor, MCU, and DSP are
reset; VCTCXO regulator forced on

Sleep Clock

t1 t2 t4t3

t1 = 20ms

t2 = 200ms

t3 = 500us

t4 = 20ms

Figure 2: Power-on sequence and timing

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Figure 3: Measured power-on sequence and timing

Power Up - Power Key

When the power key is pressed, the UEME enters the power-up sequence. Pressing the
power key grounds the PWRONX pin on the UEME. The UEME PWRONX signal is not part
of the keypad matrix. The power key is only connected to the UEME. When the power key
is pressed, an interrupt is generated to the D2800 processor that starts the MCU. The
MCU then reads the UEME interrupt register through the UEME control bus (CBUS) and
notices that it is a PWRONX interrupt. If the PWRONX signal stays low for a certain time,
the MCU accepts this as a valid power-on state and continues with the SW initialization
of the baseband. If the power key does not indicate a valid power-on situation, the MCU
powers off the baseband.

Power Up - Charger Connection

In order to be able to detect and start charging in cases where the main battery is fully
discharged (empty), charging is controlled by start-up charging circuitry.

The VBAT voltage level is monitored by the Charge Control Block (CHACON) inside the
UEME. When the VBAT level is detected to be below the master reset threshold (V

charging starts. Connecting a charger forces the Charging Voltage (VCHAR) input to rise
above the charger detection threshold (VCH

). This causes the UEME to generate

DET+

MSTR-

),

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100mA of constant output current from the connected charger’s output voltage. The
battery’s voltage rises at it charges, and when the VBAT voltage level is detected to be
higher than master reset threshold limit (V

), the start-up charge is terminated.

MSTR+

When VBAT is greater than V
internal to the UEME, is set to a Logic 1. This causes the UEME RESET block to enter into

its reset sequence.

If the VBAT is detected to fall below V
cancelled. Charging is restarted when a new rising edge on the VCHAR input is detected

(VCHAR rising above VCH

Condition Result

VBAT < V

VBAT < V

VCHAR > VCH

VBAT > V

(start-up charging) Charging starts (VCHAR level begins to rise)

MSTR-

MSTR-

DET+

MSTR+

Power Up - RTC Alarm

If the mobile terminal is in power-off mode when the RTC alarm activates, a wake-up
procedure occurs. After the baseband is powered on, an interrupt is given to the MCU.
When the RTC alarm occurs during active mode, an interrupt is generated to the MCU.

, the Master Output Reset (MSTRX) signal, which is

MSTR+

during start-up charging, charging is

MSTR-

).

DET+

Table 1: Power-up Sequence through Charger Detection

(during charging) Charging is cancelled. A new rising edge of VCHAR

(VCHAR > VCH

Battery charges (VCHAR is rising)

Charging ends. MSTRX is set high and the UEME resets.

) is required to restart charging

DET+

Power Off

The baseband switches to power-off mode if any of following occurs:

• Power key is pressed

• Battery voltage is too low (VBATT < 3.2V)

• Watchdog timer register expires

The UEME controls the power-down procedure.

Power Consumption and Operation Modes

Power-off Mode

During power-off mode, the power (VBAT) is supplied to the D2800 processor, UEME,
MMC, vibra, LED, PA, and PA drivers. During power-off mode, the UEME leakage current
consumption is approximately 40uA + 15uA from ZOCOS.

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Sleep Mode

When the SLEEPX signal is detected low by the UEME, the mobile terminal enters sleep
mode. In sleep mode, both processors (MCU and DSP) are in stand-by mode. The mobile
terminal enters sleep mode only when both processors make this request. The following
processes occur during sleep mode:

• VIO and VFLASH1 regulators are put into low quiescent current mode

• VCORE enters LDO mode

• VANA and VFLASH2 regulators are disabled

• All RF regulators are disabled

• VCTCXO (19.2MHz clock) is shut down

• 32kHz sleep clock oscillator is used as the baseband reference clock

The average current consumption of the mobile terminal in this mode can vary
depending on the software state (e.g., slot cycle 0,1, or 2, and if the mobile terminal is
working on IS95 or IS2000 for CDMA). However, on average the current consumption is
about 1.3mA in sleep mode and 100mA in active mode.

Sleep mode is exited either by the expiration of a sleep clock counter in the UEME or by
some external interrupt (e.g., charger connection, key press, headset connection). Any of
these conditions cause a high SLEEPX signal, which is detected by the UEME, and causes
the mobile terminal to enter active mode where all functions are activated.

Active Mode

During active mode, the mobile terminal is in normal operation, scanning for channels,
listening to a base station, transmitting and processing information. There are several
sub-states in the active mode depending on the mobile terminal present state of the
mobile terminal, such as burst reception, burst transmission, if the DSP is working, etc.

In active mode, software controls the UEME radio frequency (RF) regulators (VR1A and
VR1B), which can be enabled or disabled. These regulators work via the UEME charge
pump. VSIM can be enabled or disabled, and its output voltage can be programmed to be

1.8V or 3.0V. VR2 and VR4—VR7 can be enabled, disabled, or forced into low quiescent
current mode. VR3 is always enabled in active mode, disabled during sleep mode, and
cannot be controlled by the software in the same way as the other regulators. VR3 only
turns off if both processors (DSP and MCU) request to be in sleep mode.

Charging Mode

Charging mode can be performed in parallel with any other operating mode. A BSI
resistor inside the battery indicates the battery type and size and corresponds to a
specific battery capacity.

The battery voltage, temperature, size, and charging current are measured by the UEME
and controlled by the Energy Management (EM) charging algorithm.

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The charging control circuitry (CHACON) inside the UEME controls the charging current
delivered from the charger to the battery. The battery voltage rise is limited by turning
the UEME switch off when the battery voltage has reached 4.2V. The charging current is
monitored by measuring the voltage drop across a 220mOhm resistor.

Power Distribution

In normal operation, the baseband is powered from the mobile terminal‘s battery. The
battery consists of one Lithium-Ion cell capacity of 1070 mAh and some safety and
protection circuits to prevent harm to the battery.

The UEME ASIC controls the power distribution to the entire mobile terminal through the
BB and RF regulators. The battery feeds power directly to the following parts of the
system:

•UEME

•PA

•Vibra

• Display lights

• Keyboard lights

The heart of the power distribution to the mobile terminal is the UEME. The UEME
includes all the voltage regulators and feeds the power to the system. The UEME handles
hardware power-up functions so the regulators are not powered and the power-up reset
(PURX) is not released if the battery voltage is less than 2.8V.

The baseband is powered from five different UEME regulators (see Table 2):

Table 2: Baseband Regulators

Regulator

VCORE
DC/DC

VIO 150 1.8 Enabled always except during power-off mode

VFLASH1 70 2.78 Enabled always except during power-off mode

Maximum
Current (mA)

300 1.35 The power-up default value is 1.35V. The output voltage is

Vout (V) Notes

selectable: 1.0V/1.3V/1.5V/1.8V.
(Note: If using D2800 processor version 1, the default is

1.57V.)

VFLASH2 40 2.78 Enabled only when data cable is connected

VANA 80 2.78 Enabled only when the system is awake (off during sleep and

power-off modes)

VSIM 25 3.0 Enabled during power-up mode and scanning for a SIM card

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Table 3 includes the UEME RF regulators.

Table 3: RF Regulators

Regulator

VR1A 10 4.75 Enabled when cell receiver is on

VR1B 10 4.75 Enabled when the transmitter is on

VR2 100 2.78 Enabled when the transmitter is on

VR3 20 2.78 Enabled when SleepX is high

VR4 50 2.78 Enabled when the receiver is on

VR5 50 2.78 Enabled when the receiver is on

VR6 50 2.78 Enabled when the transmitter is on

VR7 45 2.78 Enabled when the receiver is on

Maximum
Current (mA)

Vout (V) Notes

The charge pump that is used by VR1A is constructed around the UEME. The charge
pump works with the 1.2MHz clock (CBUS) oscillator and gives a 4.75V regulated output
voltage to the RF.

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Clock Distribution

RFClk (19.2MHz Analog)

The main clock signal for the baseband is generated from the voltage-controlled
temperature-controlled crystal oscillator (VCTCXO). This 19.2MHz clock signal is
generated by the radio frequency circuitry and fed to the radio frequency clock (RFCLK)
pin of the D2800 processor. The 19.2MHz clock can be stopped during sleep mode by
disabling the UEME regulator output (VR3), which in turn powers off the VCTCXO.

Figure 4: Waveform of the 19.2MHz clock (VCTCXO)

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RFConvClk (19.2MHz Digital)

The D2800 processor distributes the 19.2MHz clock to the internal processors (the DSP
and MCU) where the software multiplies this clock by seven (=134.4MHz) for the DSP
and by two (=38.4MHz) for the MCU.

Figure 5: RFCovCLk waveform

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CBUSClk Interface

CBUS utilizes a 1.2MHz clock signal, which is used by the MCU to transfer data between
the UEME and the D2800 processor.

Figure 6: CBUS data transfer

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DBUS Clk Interface

DBUS utilizes a 9.6MHz clock signal, which is used by the DSP to transfer data between
the UEME and the D2800 processor.

Figure 7: DBUS data transfer

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SleepCLK (Digital)

The UEME provides a 32kHz sleep clock for internal use and also to the D2800 processor,
where it is used for the sleep-mode timing.

Figure 8: 32 kHz Digital output from UEME

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SleepCLK (Analog)

When the system enters sleep mode or power-off mode, the external 32KHz crystal
provides a reference to the UEME. The RTC circuit also uses this clock to turn on the
mobile terminal during power-off or sleep mode.

Figure 9: 32KHz analog waveform at 32KHz crystal input

Flash Programming

Connections to Baseband

The flash programming equipment is connected to the baseband using test pads for
galvanic connection. The test pads are allocated in such a way that they can be accessed
when the mobile terminal is already assembled. The flash programming interface
includes the VPP, FBUSTX, FBUSRX, MBUS, and BSI signals, which are used by the FLS-8
for flashing. The connection is through the UEME, which means that the logic voltage
levels of these signals correspond to 2.78V. Power is supplied to the mobile terminal
using the battery contacts.

Baseband Power Up

The baseband power is controlled by the flash prommer in production and in
re-programming situations. The baseband powers up by applying supply voltage to the
battery terminals. After the baseband is powered up, flash programming indication
begins (see the following "Flash Programming Indication" section).

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Flash Programming Indication

After connecting the flash prommer to the mobile terminal, the flash prommer sets the
MBUS line low to notify the MCU that the flash prommer is connected. This causes the
UEME reset state machine to perform a reset to the system by setting the PURX signal
low for 20ms.

During flash programming, the MBUS signal transmitted from the UEME to the flash
prommer is used as the clock for synchronous communication. This MBUS clock is also
supplied by the UEME to the D2800 processor, along with the MBUSRX signal. If the
MBUSRX signal is low, the MCU enters flash programming mode. To avoid accidental
entry into flash-programming mode, the MCU waits to get input data from the flash
prommer. If the timer expires without any data being received, the MCU continues the
boot sequence.

When the mobile terminal has entered flash programming mode, the flash prommer
writes an 8-bit password to the UEME to indicate that flash programming/
reprogramming is to take place. This 8-bit data is transmitted through the FBUSRX line
into a shift register inside the UEME. When the 8 bits have been shifted into the register,
the flash prommer generates a falling edge on the BSI line. This loads the shift register
content into a comparison register inside the UEME. If the 8 bits in the comparison
register matches the default value preset in the UEME, programming starts.

Flashing

In order to avoid spurious loading of the register, the BSI signal is gated during UEME
master reset and during power up when the PURX is active (low). The BSI signal must not
change states during normal operation unless the battery is extracted. If the battery is
extracted, the BSI signal is pulled high.

Note: A falling edge is required to load the comparison register.

The UEME flash programming mode is valid until the MCU sets a bit in the UEME register
that indicates the end of flash programming. Setting this bit also clears the comparison
register in the UEME previously loaded at the falling edge of the BSI signal. During the
flash programming mode, the UEME watchdogs are disabled. Setting the bit indicating
the end of flash programming enables and resets the UEME watchdog timer to its default
value. Clearing the flash programming bit also causes the UEME to generate a reset to
the D2800 processor.

Flash programming is done through the VPP, FBUSTX, FBUSRX, MBUS, and BSI signals.

When the mobile terminal enters flash programming mode, the prommer indicates that
flash programming will take place by writing an 8-bit password to the UEME. The
prommer sets the BSI value to “1” and then uses FBUSRX for writing and MBUS for
clocking. The BSI is then set back to “0”.

The MCU uses the FBUSTX signal to indicates to the prommer that it has been noticed.
After this, the MCU reports the ID type to the D2800 processor and is ready to receive
the secondary boot code to its internal SRAM.

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FLASH_1

CH1 = BSI
CH2 = MBUS
CH3 = FBUSTX
CH4 = FBUSRX

Measure points
Production test pattern
(J396)

Figure 10: Flashing starts by BSI being pulled up and password being sent to UEME

This boot code asks the MCU to report the mobile terminal’s configuration information
to the prommer, including the flash device type. The prommer can then select and send
the algorithm code to the MCU SRAM and SRAM/Flash self-tests can be executed.

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FLASH_2

CH1 = PURX
CH2 = MBUS
CH3 = FBUSTX
CH4 = FBUSRX

Measure points
Production test pattern
(J396)

Figure 11: Flashing, continued

• Ch1= PURX

• Ch2 = MBUS toggled three times for MCU initialization

• Ch3 = FBUS_TX low, MCU indicates that prommer has been noticed

• Ch4 = FBUS_RX

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FLASH_3

CH1 = PURX
CH2 = MBUS
CH3 = FBUSTX
CH4 = FBUSRX

Measure points
Produ ction test pattern
(J396)

Data transfer has
started (Fbus_Rx)

Figure 12: Flashing, continued 2

Flash Programming Error Codes

The following characteristics apply to the information in Table 4.

• Error codes can be seen from the test results or from Phoenix's flash-tool.

• Underlined information means that the connection under consideration is being
used for the first time.

Table 4: Flash Programming Error Codes

Error Description Not Working Properly

C101 "The Phone does not set FbusTx line high after

the startup."

C102 "The Phone does not set FbusTx line low after

the line has been high. The Prommer generates
this error also when the Phone is not con­nected to the Prommer."

Vflash1
VBatt
BSI and FbusRX from prommer to UEME.
FbusTx from UPP->UEME->Prommer(SA0)

PURX(also to Safari)
VR3
Rfclock(VCTCXO->Safari->UPP)
Mbus from Prommer->UEME­>UPP(MbusRx)(SA0)
FbusTx from UPP->UEME->Prommer(SA1)
BSI and FbusRX from prommer to UEME.

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Table 4: Flash Programming Error Codes (Continued)

Error Description Not Working Properly

C103 " Boot serial line fail." Mbus from Prommer->UEME-

>UPP(MbusRx)(SA1)
FbusRx from Prommer->UEME->UPP
FbusTx from UPP->UEME->Prommer

C104 "MCU ID message sending failed in the Phone." FbusTx from UPP->UEME->Prommer

C105 "The Phone has not received Secondary boot

codes length bytes correctly."

C106 "The Phone has not received Secondary code

bytes correctly."

C107 "The Phone MCU can not start Secondary code

correctly."

C586 "The erasing status response from the Phone

informs about fail."

C686 "The programming status response from the

Phone informs about fail."

Cx81 "The Prommer has detected a checksum error

in the message, which it has received from the
Phone."

Cx82 "The Prommer has detected a wrong ID byte in

the message, which it has received from the
Phone."

A204

Cx83

Cx84

"The flash manufacturer and device IDs in the
existing algorithm files do not match with the
IDs received from the target phone."

"The Prommer has not received phone
acknowledge to the message."

"The phone has generated NAK signal during
data block transfer."

Mbus from Prommer->UEME->UPP(MbusRx)
FbusRx from Prommer->UEME->UPP
FbusTx from UPP->UEME->Prommer

Mbus from Prommer->UEME->UPP(MbusRx)
FbusRx from Prommer->UEME->UPP
FbusTx from UPP->UEME->Prommer

UPP

Flash

Flash

FbusTx from UPP->UEME->Prommer

FbusTx from UPP->UEME->Prommer

Flash
UPP
VIO/VANA
Signals between UPP-Flash
Mbus from Prommer->UEME->UPP(MbusRx)
FbusRx from Prommer->UEME->UPP
FbusTx from UPP->UEME->Prommer

Cx85

Cx87 "Wrong MCU ID." RFClock

Startup
for
flashing

"Data block handling timeout"

UPP(Vcore)

Required startup for flashing Vflash1

VBatt

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Charging Operation

Battery

The mobile terminal uses a Lithium-Ion cell battery (BL-6C) with a capacity of 1070mAh.
Reading a resistor inside the battery pack on the BSI line indicates the battery size. An
NTC resistor close to the SIM connector measures the mobile terminal’s temperature on
the BTEMP line. Temperature and capacity information are needed for charge control.
These resistors are connected to the BSI pins on the UEM. The mobile terminal has
100KΏ pull-up resistors for these lines so that they can be read by A/D inputs in the
mobile terminal.

Figure 13: BL-5C battery pack pin order

Charging Circuitry

The UEME ASIC controls charging depending on the charger being used and the battery
size. External components are needed for Electromagnetic Compliance (EMC), reverse
polarity, and transient protection of the input to the baseband module. The charger
connection is through the system connector interface. The baseband is designed to
support DCT3 and higher chargers from an electrical point of view. Both 2- and 3-wire
type chargers are supported. However, the 3-wire charger is treated as a 2-wire charger.

Figure 14: Charging circuitry

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Charger Detection

Connecting a charger creates voltage on the VCHAR input of the UEME. Charging starts
when the UEME detects the VCHAR input voltage level above 2 V (VCH

threshold).

det+

The VCHARDET signal is generated to indicate the presence of the charger for the SW.
The EM SW controls the charger identification/acceptance.

The charger recognition is initiated when the EM SW receives a ”charger connected”
interrupt. The algorithm basically consists of the following 3 steps:

1. Check that the charger output (voltage and current) is within safety limits.

2. Identify the charger as a 2-wire or 3-wire charger.

3. Check that the charger is within the charger window (voltage and current).

If the charger is accepted and identified, the appropriate charging algorithm is initiated.

Audio

Figure 15: Charging circuit

The audio control and processing is provided by the UEME, which contains the audio
codec, and by the D2800 processor, which contains the MCU and DSP blocks. These
blocks handle and process the audio data signals.

The baseband supports three microphone inputs and two earpiece outputs. The
microphone inputs are MIC1, MIC2, and MIC3:

• MIC1 is used for the mobile terminal's internal microphone

• MIC2 is used for headsets (HDB-4)

• MIC3 is used for the Universal Headset

Every microphone input can have either a differential or single-ended AC connection to
the UEME circuit. The internal microphone (MIC1) and external microphone (MIC2) for

Pop-portTM accessory detection are both differential. However, the Universal Headset
interface is single-ended. The microphone signals from different sources are connected
to separate inputs at the UEME. Inputs for the microphone signals are differential types.
Also, MICB1 is used for MIC1 and MICB2 is used for MIC2 and MIC3 (Universal Headset).

Displays and Keymat

The mobile terminal utilizes the main display and a secondary display, as well as an
electroluminescent (EL) panel for the keymat lighting.

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Main Display

There are three LEDs for the main display, which utilize the KLIGHT signal. Table 5 shows
the characteristics of the main display.

Table 5: Main Display Characteristics

Parameter Value

Technology Active matrix (TFD)

Resolution 160 x 128

Number of LEDs 4

Number of colors 64K

Interface Messi-8 (parallel)

Illumination mode White (default)

Figure 16: Waveform for the main display interface

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Secondary Display

There are three LEDs for the secondary display, which utilize the DLIGHT signal. Table 5
shows the characteristics of the secondary display.

Table 6: Secondary Display Characteristics

Parameter Value

Technology Passive (C-STN)

Resolution 96 x 65

Number of LEDs 3

Number of colors 4096

Interface LoSSI (serial)

Illumination mode Black (default)

Keymat

An EL panel is used for keymat illumination, which is controlled by the GPIO(57) signal.

Camera

The following block diagram shows the camera and HWA connections to the baseband.

Figure 17: Camera and HWA connections to the baseband

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DC Measurements

Table 7: Power Supply Characteristics

Signal Name

VIO 1.8 1.7 1.8 1.9 V Control line

VANA (Vflash2) 2.79 2.7 2.78 2.9 V Analogue supply

VDIG 1.79 1.7 1.8 1.9 V Digital supply

GND 0 0 V System GND

Signal Name

CSX H = 1.80

DaClk H = 1.77

TxDa H = 1.75

Measured
Value (V)

Measured
Value (V)

L = 2.0m

L = -18m

L = -18m

Min Typical Max Unit Description

Table 8: DC Characteristics

Min Typical Max Unit Description

H = 0.7xVIO
L = 0

H = 0.7xVIO
L = 0

H = 0.8xVIO
L = 0

H = VIO
L: 0.3xVIO

H= VIO
L= 0.3xVIO

H = VIO
L = 0.2xVIO

V Camera chip select

V Voltage levels

V Data to transmit,

(active low)

camera interrupt
(active low)

RxDa H = 1.76

L = -11m

ExtClk H = 1.75

L = -12m

VCtrl N/A H = 0.7xVIO

Note: H stands for high signal level and L for low signal level.

H = 0.7xVIO
L = 0

0.5Vp-p 1Vp-p VIOp-p V All modes

L = 0

H = VIO
L = 0.3xVIO

H = VIO
L = 0.3xVIO

V Data to receive

V Logic 0: shutdown

AC Measurements

Table 9: AC Measurement Characteristics

Signal Name

DaCLK F = 4.799 4.69 4.8 4.81 MHz Frequency

ExtClk F = 9.6 9.59 9.6 9.69 MHz External system clock

Measured
Value (V)

D = 49.4 45/55 50/50 55/45 % Duty cycle

D = 49.3 45/55 50/50 45/55 %

Min Typical Max Unit Description

(mode 4)

Note: DaClk frequency will not exceed ExtClk/2

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FM Radio

FM radio circuitry is implemented using highly integrated radio IC, TEA5767HN. FM radio
circuitry is controlled through the serial bus (GenIOs) interface from MCU SW.

Figure 18: FM Radio (N356), Audio (N150), antenna, and digital interface connections

Stereo audio output signals are fed to the stereo amplifier. Volume control of the FM
audio signal is made by circuitry inside the amplifier. The amplified audio signal is fed to
the headset or IHF speaker. The headset is also used as an antenna input for the radio.

FM Radio Test

To hear the FM radio, connect the headset to the Pop-port or UHJ ports because the
headset is the FM radio antenna. Also, connect the headset to an UHJ port to control the
FM radio using Phoenix. However, if you connect a headset (e.g., HDS-3) to a Pop-port
connector, then you cannot control the mobile terminal because you have already
occupied the connection port (Pop-port). In this case you have to have jumper wires on
the production test points (Fbus Tx/RX, GND).

Input Signals to the FM Radio

After connecting a headset to the UHJ port to control the mobile terminal through
Phoenix, you can see the following signals by turning on the FM radio in Phoenix (which
is in the RF menu).

Check the following signals to see whether they are changed as represented in Figure 19:

• FMClk = Test Point (FM04) : 32KHz/1.8V

• FMWrEn = Test Point (FM03) : Write enable at 1.8V

• FMCtrlClk = Test Point (FM02) : Control clock at 1.8V

• FMCtrlDa = Test Point (FM01) : Control data at 1.8V

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Figure 19: FM Radio signals before Radio on

• Ch1 : FMClk(32.768KHz)

• Ch2 : FMWrEn

• Ch3 : FMctrlClk

• Ch4 : FMctrlDA

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USB Interface

The USB (Universal Serial Bus) allows up to 127 devices to be attached via a tree-like
structure of hubs and devices all emanating from one root host. Devices can be attached
or detached at any time without concern for rebooting the PC or loading device driver
software. Detection of attachment or detachment is done automatically and requires no
user input.

The mobile terminal is a full speed peripheral device, and as such, communicates with
the host PC at 12Mbps. Full speed USB allows for fast transfer of large data formats
(MP3, JPEG, AVI, etc.). When the mobile terminal is used as a modem, a fast interconnect
with the PC is required.

The mobile terminal incorporates the portal USB engine. This engine is supported using
an ASIC core supplied by TI. This core is called the Wireless Function Controller 2 (W2FC)
and is included in the D2800 processor IC. The core completes several USB functions
automatically and is controlled by the ARM9 MCU.

Because the D2800 processor's IO cells are restricted to 1.8V, the Nokia USB Transceiver
(NUT) is used as a data-level, shifting and conditioning ASIC. NUT provides the interface
between the ASIC's 1.8V bus and the 3.3V USB bus. Before the USB signals are passed to
the system connector, they pass through an Application Specific Integrated Passive
(ASIP) that integrates five passive components and provides >8kV ESD protection for the
external data and power supply lines.

Figure 20: FM Radio signals after Radio on

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System

System
Vctcxo

Vctcxo

ARM MCU

48MH z

48MH z

DPLL

DPLL

NUT_Fbus

NUT_speed

PVCI Bus,

IRQ s,

DM A control

CLK48I

TIKUEdge

W2FC

SUSPEND O

PUENO

GZO

RXDI

RXDM I

RXDPI

SE0O

TXDO

Genio #

Genio #

Genio #

USBOEx

USBRCV

USBVM

USBVP_FRX

USBFSE0_FTX

USBVO

Genio #

VAUX3

UEME

NUT

Vreg
SEmode

_Speed

Pull_up_en

OE#
RCV

Vm
Vp/Frx

FSe0/Ftx

VO
Suspend

VIO

Vsw

Vcc

3.3V

D+/RXD

D-/TXD

VIO

220KO hm

33R
33R

USB ASIP

10K

1K3

Zener D iode

ESD Protection

(>8K v )

System
Connector

Vbus

D+

D-

GND

GND

Figure 21: USB interface block diagram

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The USB consists of four signals:

Table 10: USB Signals

Signal Description

Vbus 5V Power supply from host to device

D+ Differential data signal (swings between 0 and +3.3V)

D- Differential data signal (swings between 0 and +3.3V)

GND Ties host and device ground together

When the mobile terminal is attached to a USB host, the host provides a 5V supply at the
Vbus pin of the system connector. The NUT indicates the presence of the host to the
W2FC by altering the state of Vp and Vm as shown in Table 11.

Table 11: Vp and Vm States

Vcc Vp Vm

0V Logic 1 Logic 1

5V Same logic as D+ Same logic as D-

After the USB host is connected, D+ and D- are pulled to GND by 15kW resistors at the
host end. In turn, the Vp and Vm are pulled low. Any state other than Vp=Vm=1
generates a wake request interrupt. When the NMP software receives this interrupt, it
enables the 48MHz clock and wakes the MCU from deep sleep.

When the NMP software is ready to communicate with the USB host, it asserts the

1.3kW pull up on the D+ signal by instructing the W2FC to assert its PUENO signal. The
NUT detects this and ties the D+ signal to a 3.3V supply through the 1.3kW pull up. The
W2FC brings the NUT out of suspend by setting SUSPEND low. The NUT now draws the
majority of its current from the USB host 5V supply.

The USB host detects a high state on the D+ line and recognizes that a USB device is
attached. 100ms later, the USB host drives a reset for 10ms by driving D+ and D- low.
Following the reset, the USB host starts to drive data across the D+ and D- lines,
requesting configuration information from the device. The NUT level shifts and
conditions this data, presenting it to the W2FC on its RCV, Vp and Vm pins.

Once the W2FC has decoded the received data, it begins transmitting back to the USB
host by asserting the NUT's active low OE pin and then driving data on the NUT's VO pin.
After some level shifting and conditioning, the NUT drives the D+ and D- lines with this
data.

The USB Tx and Rx continue in this fashion controlled by the USB host.

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Accessories

The 6255/6255i/6256/6256i supports Pop-port and Universal Headset accessories,
differential and single-ended, respectively. Detection of the Pop-port accessories is done
through the ACI signal where the Universal Headset is detected on TIKU_GenIO (4).

Figure 22: Pop-port connector pin out

The pin out on the Pop-port connector is as follows:

•Charger

• Charger GND

•ACI

•Vout

•USB Vbus

• USB D+ / Fbus Rx

•USB D- / Fbus Tx

• Data GND

•XMic N

•XMic P

•HSear N

•HSear P

•HSear R N

•HSear R P

You can perform the following in Pop-port accessories:

• Charging

• Accessory detection

• FBUS communication

• USB communication

• Fully differential audio interface for mono- and stereo outputs

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Charging

Charging through Pop-port is accomplished in the same manner as through the charger
connector. Pin 1 of the Pop-port is physically connected to the charger connector. When
the mobile terminal is connected to a desktop charger (e.g., DCV-15), it charges in the
same manner as it does with the charger connector.

Figure 23 shows the actual charging sequence. The channels on the diagram are:

• CH1 = Charging current across the .22 Ohm (R200) resistor on UEMEK

• CH2 = Charger voltage measure at V100

• CH3 = Battery voltage measure at R200

•CH4 = PURX

Figure 23: Charging sequence

In Channel 4, PURX is released, which this indicates when the mobile terminal operation
goes from RESET mode to POWER_ON mode.

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Pop-port Headset Detection

Accessory detection on the Pop-port is done digitally. The pins used for this accessory
detection are:

• Pin 2 (Charge GND)

• Pin 3 (ACI)

•Pin 4 (Vout)

Figure 24: Waveform showing Pop-port accessory detection

FBus Detection

FBus communication in Pop-port is done through the following lines:

• Pin 2 (Charge GND)

• Pin 3 (ACI)

•Pin 4 (Vout)

• Pin 6 (FBus Rx)

• Pin 7 (FBus Tx)

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Figure 25: Waveform showing Pop-port FBus communication

Accessory Detection Through ACI

USB and Audio on (mono or stereo)/FM radio communication in Pop-port is done
through the following signals:

Table 12: Accessory Detection Signals

USB Audio/FM

Pin 5 (USB Vbus) Pin 9 (XMic N)

Pin 6 (USB +) Pin 10 (SMIC P)

Pin 7 (USB -) Pin 11 (HSEAR N)

Pin 8 (Data GND) Pin 12 (HSEAR P)

Pin 13 (HSEAR R N)

Pin 14 (HSEAR R P)

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Figure 26: Waveform showing accessory detection through ACI

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RUIM (SIM CAR)

The 6255/6255i/6256/6256i supports SIM CAR. Use the waveform in Figure 27 to verify
that the sim_vcc, sim_i/o, cim_clk, and sim_rst signals are activated in the correct
sequence at power up. This picture may be taken when the SIM CAR is installed on the
mobile terminal to measure the signals when the mobile terminal is turned on. The figure
shows the proper waveforms when the interface is working. See Figure 28 on page 41 for
the test point’s location.

Figure 27: RUIM signal waveform

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Main Display Test Points

BSI

VBAT

GND

SLEEP_CLK

CBUS_EN

CBUS_DA

MICB1

CBUS_CLK

MICB2

RFBUS_CLK

PURX

Figure 28: Main display test points - top

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SIMDAO

SIMCLKO

SIMRST

VSIM

Vibra

SLEEPX

VIO

VFLASH1

MMC card

Figure 29: Main display test points - bottom - 1

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VANA

VR3

VR7
VR6
VR2

19.2MHz Clk

VSIM

FBUSTXO

MBUS

FBUSRXO

VR5
VR4

VR1A
VR1B

MMC_VCC

MMC_CLKL

MMC_DATA

VCORE_LIN

Figure 30: Main display test points - bottom - 2

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Flex
connector

POWERON_X

LCDCAM_CLK

Figure 31: Main display test points - bottom - 3

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







Nokia Customer Care Baseband Description and Troubleshooting

Secondary Display Test Points

GPS_U2TX

VIO

Earpiece_1 Earpiece_2

GPS_U2RX

GND

Figure 32: Secondary display test points - top

V LED +

Secondary display

Secondary display
driver enable





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GPS_INT_UI_CLK

GPS_UI_TX

GPS_EN_RST

CALLED2

DLIGHT

BT_VART_RX

CAM_LED_EN

19.2HMz_GPS

VLED

GPS_UI_RX
KLIGHT

Camera flash strobe

Camera key 1

Camera key 2

VLED

Camera_Clk
Camera CE

VLED

Figure 33: Secondary display test points - bottom - 1

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VFLASH_LIGHT

Camera flash driver

VBAT

Figure 34: Secondary display test points - bottom - 2

LED driver

Camera

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GPS Module

The GPS circuitry utilizes RF signals from satellites stationed in geosynchronous orbit to
determine longitude and latitude of the handset. The GPS circuitry is completely separate
of the CE circuitry and is located almost exclusively on the secondary side of the PWB
underneath the display module.

Figure 35: GPS Block Diagram

Use the following steps for basic GPS BB troubleshooting:

1. Always perform a visual inspection on the GPS circuitry to see if the problem is
physical (dislodged parts, corrosion, poor solder joints, etc.) before performing a
diagnostic test.

2. Put the GE and CE in the proper mode

3. Check to make sure that necessary inputs from the CE are good (power, clock,
etc.).

4. Ensure that these inputs produce the proper outputs.

Because of the large level of integration (most functionality is contained in the two ASIC
chips), the amount of diagnostics one is able to do is limited.

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Troubleshooting

The following hints allow you to find the cause of the problem when the circuitry seems
to be faulty. Troubleshooting instructions are divided into the following sections:

• Mobile terminal is totally dead

• Flash programming does not work

• Power does not stay on or the mobile terminal is jammed

• Charger faults

• Audio faults

•Display faults

•Keypad faults

•USB

• MMC

•FM Radio

•Camera

• Bluetooth

•SIM

•GPS

First, carry out a through visual check of the module. Ensure in particular that:

• There are no mechanical damages

• Soldered joints are okay

• ASIC orientations are okay

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Mobile Terminal is Totally Dead

¾ If current is zero, check X2002 to make sure

Mobile

terminal is

dead

Vbat makes contact.

¾ If current is too high, check for shorts.

¾ Make sure all BB regulators are at their

respective voltage levels (VANA, VIO,
VCORE, VFlash1, and VR3). See phone's top
view diagram for test points.

Mobile termninal

current is zero or

too high?

NO

Mobile terminal

current is

<=30 mA

NO

Mobile terminal

current is

35 mA

YES

YES

YES

NO

¾ Make sure the system Clk is 19.2MHz and that

the sleep Clk is 32KHz.

¾ Make sure PURX and SleepX signals are high

(1.8V).

Is mobile terminal

flash programming

OK?

NO

YES

Mobile

terminal is

jammed

Flash
faults

Check BSI line

Is mobile terminal in

Local Mode?

NO YES

X2002, R2202,

R2205, and C2015.

Change UEM

Are they OK?

YES

NO

Repair

OK restart

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Flash Programming Does Not Work

Flash

faults

The m obile ter minal

does not set

Flashbus TXD line

high after the

startup

NO

YES

Measure BSI pulse during

Flash programming. Is it

OK?

YES

Measure FBusRXO (2.78V)

signal during flash
programming from

production pattern and

FBUSRX test point (1.8V).

Is it the same?

YES

NO

NO

Check BSI line

X2002, C2015,

R2202, R2205

Reflow or

change UEM

Change UPP

Does the mobile

terminal set

Flashbus TXD line

low after the line has

been high?

Yes

Flash

faults,

page 2

No

Change

UEM

Measure test point
FBusTx (1.8V) and

production pattern signal

FBusTxO (2.78V) during

flash programming. Are

they the same?

YES

Measure MBusRx (2.78V)

and M BUS (1 .8V). Are t hey

the same?

NO

NO

NO

Is there a pulse

on FBusTx?

Yes

Is there a pulse

on FBusTxO?

NO

Reflow or

change UEM

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Flash

Faults

Page 2

Can you read the

manufacturer ID and

the device ID?

YES

Is the mobile

terminal totally

dead?

NO

Does the mobile

terminal not start up

or is the phone

jammed?

YES

Re-flow the flash. Is

NO

YES

YES

terminal is

terminal is

it OK?

Mobile

dead

Mobile

jammed

Re-flow the UPP. Is

NO

it OK?

Retest

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Power Does Not Stay on or the Mobile Terminal is Jammed

Mobile

terminal is

jammed

Measure VIO,

VCORE, VFlash1,

VANA, and VR3

voltages. Are they

OK?

YES

Measure 32kHz

Sleep Clk test

points. Are they OK?

YES

Check VBATT, VIO,

VCORE, VFlash1,

VANA, VR3 capacitors.

Are they OK?

NO

YES

Check BSI/BTEMP

lines and VBATT lines.

If OK, reflow or

change UEM

Measure the 32kHz Clk

NO NO

crystal. Is it OK?

YES

Reflow or change UEM

NO

Repair

Change B2200

Measure 19.2MHz RF

Clk testpoint. Is it

OK?

YES

Measure PURX

(TP16) and SleepX

(TP10). Are they

high (1.8V)?

YES

Mobile

terminal is

jammed,

page 2

Measure the 19.2MHz

NO NO

Clk coming from the

VCTCXO at C7205. Is it

OK?

YES

Check R517, R521,
and D527. Are they

NO

OK?

YES

Change UPP

NO

Is PURX OK?

YES

Is PURX OK?

YES

NO

NO

Check G7200,

R7200, C7200,

C7203, R7205, and

C7207.

Repair

Change UEM

Change UPP

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Mobile

terminal is

jammed,

page 2

Mobile terminal

shutdown after 32

seconds

NO

Measure DBusClk

(9.6 MHz), Data, and

EnX signals. Are

they OK?

YES

Read mobile

terminal info. Is it

OK?

YES

Retest

Has the mobile

YES NO

terminal been

flashed?

YES

Measure watchdog

NO

signal Cbus. Is it

OK?

Reflow or

YES

change UPP.

Measure FBusRx

NO NO

signal during phone

info read. Is it OK?

YES

Measure FBusTx
signal during mobile
terminal info read. Is

it OK?

YES

NO

NO

Flash the mobile

terminal

Reflow or change

UPP and reflash.

Reflow or change

UEM and reflash.

Reflow or change

UEM.

Reflow or change

UPP.

Reflow or change

UEM.

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Charger Faults

Charger

faults

Connect Charger.

Make sure battery is

connected.

Battery bar doesn't

work (scroll)

YES

Measure voltage

over V2000. Is it >3.0

Vdc?

YES

Read BTEMP value.

Is it ~25C?

YES

NO

NO

NO

Retest

Check X2001, F2000,

L2006, V2000,

C2012, and C2013.

Change UEM

Remove (fuse) F100

and measure current

with an ACP9

NO

Change UEM

charger.

Is it ~350mA?

YES

Retest

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Audio Faults

Earpiece

Audio

faults

Is the earpiece

working?

YES

NO YES

Set phone in Local Mode. Use

Phoenix Troubleshooting >

Phone Co ntrol > Phone State

tab > Select Local Mode > click

Execute. Then use Autio Test >

HP m icrophone in/HP speaker

out > Loop ON to enable

earpiece. Inject a 1KHz sine

signal 200Vp-p on XMIC.

Change

earpiece. Is it

working now?

NO

Is the signal

coming out of

the UE M o n

EARP and

EARN?

YES

NO

Retest

Check UE M. If

not OK, change

the U E M .

Check the

earpiece

connection and

pads.

Audio
faults ,

page 2

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Microphone

Audio

faults ,

page 2

Is the

microphone

working?

YES

Change the

NO YES

microphone. Is it

working now?

NO

Set mob ile termina l in L o c al

Mode. Use Phoenix

Troubleshooting > P hone

Control > Aphone State Tab >

select Local Mode > click

Execute. Then use Audio test >

HP microphone in/HP speaker

out > L o o p O N to e n ab le th e

earpiec e . T a lk th ro ugh th e

microphone.

Measure MICB1

voltage from MICP

pads on bottom

connector.

Is it ~2 .1 V ?

YES

Is the sig n a l g oin g

to the U E M at M IC1P

and MIC1N at C2113

and C2114?

YES

NO

NO

Retest

Check C2115. If

OK, change U EM.

Check audio

ASIPs Z2105,

Z2106, C2113 and

C2114, then

change the

microphone.

Is the sig n a l g oin g

out o f th e U EM a t

HSEARP, pin 12 on

the b o tto m

Check R10 6. If OK,

NO

change the UEM .

connector?

YES

Audio

faults ,

page 3

Retest

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IHF

Audio
faults,

page 3

Check IHF audio

Is IHF working?

YES

NO NO

Set the phone to Local Mode. Use

Phoenix to open Troubleshooting >

Phone Control > Phone State tab >

select Local Mode > click Execute.

Then use Audio test > HP

microphone in/ Ext speaker out >

Loop ON. Measure and check IHF

test points IHFA and IHFB.

amplifier

(N2100). Is it

OK?

YES

Are they OK?

Replace N2100.

Check R117,

NO

R2118, R2119. If

OK, change the

UEMEK.

Audio
faults,

page 4

YES

Change IHF speaker.

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Vibra

Audio

fau lts,

page 4

Is V ib ra

working?

YES

Measure VBATT

NO NO

Vibrating Alert > Select On >

voltage pin 1 of

M2 4 0 0. Is it OK ?

YES

Use the UI Menu > Profile >

Normal > C ustom ize >

then go back to Custom ize
Menu > Ringing Tone > Try

any ring tone. Does the

vibra work?

YES

Measure the

UEM signal on

pin 2 of M2400.

Is th e s ig n a l O K?

YES

Change Vibra

NO

Check VBATT

line

Change the UEM

END

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Display Faults

Main Display

Main

Display

faults

Are the UI module

and display LEDs

turned on when the

mobile terminal is

turned on or when

making a call?

NO NO

Measure KLIGHT at

R2455, Vbat at

C2451, and Pout at

C2453. Are they OK?

YES

If Vbat is not OK,

check the battery. If

Pout is not OK,

check N2450.

YES

Measure test point

X2453 (~>12). Is it

OK?

YES

Check X2463. Is it

OK?

YES

Measure the

KLIGHT.

Is the signal OK?

YES

Check display

module. Is it OK?

NO

NO

NO

NO

Replace

Replace

Change UEM

Replace display

module.

YES

Main

Display

faults,

Retest

page 2

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Main

Display

faults,

page 2

Does the Display

show an image?

YES

Try changing

NO YES

display module.

Is it OK?

NO

Measure VIO and

VFLASH1. Is it

NO

OK?

Check LCD signals
LCDCSX, LCDCLK,

LCDDA, and XRES. Are

the signals OK? (Refe r
to the display section.)

YES

Retest

Change UEM

NO

Change UPP

Change Display

END

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Secondary Display

Secondary

Display

faults

Are the secondary

display LEDs on?

YES

NO NO

Check N2451. Is it

OK?

YES

Check Vbat at

C2470. Is it OK?

YES

NO

Check V2450, V2451,

and V2452. Are they

NO

OK?

YES

Check C2468,

C2469, and R2457.

NO

Are they OK?

Replace the N2451.

Check Vbat

connector and

battery.

Replace LEDs.

Replace

YES

END

Check DLIGHT. Is it

OK?

YES

Retest

NO

Replace the UEM.

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Keypad Faults

Power Key

Keypad

faults

Is the power key

working?

YES

Keypad

faults,
page 2

Measure voltage

NO NO

at pin 1 and 3

(S300). Is it

high?

YES

Measure voltage

at pin 1 and 3

(S300) when the

power key is

YES

pressed. Is it

high?

NO

Mobile terminal

is Jammed

C314, and R304.

If OK, change

Check S300. Is it

OK?

NO

Change S300

Check S300,

UEM

Mobile terminal

YES

dead

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UI Modules

Keypad

fault s,

page 2

Are UI modules

keys working?

YES

Change keypads

NO YES

mo d u le. Is it

working?

NO

Measure ROW 0-4

Ke yb (5 ) a n d

Ke yb (9 ) s ig n a ls

between UPP and

YES

Z2400. Are they

~1.8V?

NO

Make sure there

are no shorts on

YES

Z24 00 . Is it O K ?

NO

Retest

Retest

Change the UPP.

END

Change Z2400

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Nokia Customer Care Baseband Description and Troubleshooting

EL Panel and Driver

EL Panel

and Driver

Faults

Is the keypad
backlight on?

YES

EL Panel

OK

NO

Check

Tiku_GPIO(57). Is it

OK?

YES

Che c k N240 0 . Is it

OK?

YES

Is the root EL power

180Vpf-pk?

YES

Ch ec k E L p an e l. Is it

OK?

NO

NO

NO

Replace D2800

Replace N2400

NO

Replace EL panel

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USB

Before proceeding with the USB faults troubleshooting portion of this guide, attach a
DKU-2 cable between the mobile terminal and the PC. The PC must recognize that a USB
device has been attached and load driver(s) for that device. The mobile terminal appears
in the Device Manager dialog box.

Figure 36: Device Manager dialog box

If the mobile terminal appears, the USB device detection protocol is functioning and
indicates this is not a hardware fault. No further troubleshooting is possible.

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If no device is detected, proceed as follows:

USB faults

Check continuity

between system

connector pin 5 and

R1053

YES

NO

Replace system

connector

Check continuity

between system

connector pin 6 and

R1054

YES

Check continuity

between system

connector pin 7 and

R1055

YES

Check continuity

between system

connector pin 8 and

phone ground

Yes

NO

NO

NO

Replace system

connector

Replace system

connector

Replace system

connector

USB faults

page 2

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USB faults

page 2

Attach DKU-2 cable

between PC and

phone

YES

USB host not

Check for ~5V on

C1022

NO

Check for ~5V on

Z101

NO

supplying VBUS,

check connection to

PC

YES

Check for ~2.8V on

pin 6 of system

connector

Yes

USB faults

page 3

YES

Replace R1190

Check for ~2.8V on

R11287

YES

Replace USB ASIP

NONO

Replace NUT and

check for ~2.8V on

R1187

YES

Retest

NO

Replace D2800

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USB faults

page 3

Check for ~0V on pin

7 of system

connector

YES

Hardware

functioning properly

NO

Check for ~0V on

Replace USB ASIP

J960

YES

NO

Replace NUT and
check for ~0V on

J960

YES

Retest

NO

Replace D2800

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MMC

The hardware of the MMC interface from the UEME (D2200) to the MMC connector
(X3200) cannot be tested without an MMC card. Solder wires on respective points to be
able to measure the following.

MMC faults

Measure VBAT at
C3200 = 3.7-4.2V?

YES

The following points

can be measured at

phone power up

because the MMC is

initialized here.

Measure VMMC at

C2301=2.85V

YES

Measure VMMC at

X3200 pin 5 = 2.85V

NO

NO

NO

Defective PWB

Replace N3200

Resolder X3200

YES

Measure MMC_CMD

and MMC_CLK

activity on X3200,

pins 7 and 4

YES

Re-flash phone

NO

Replace R3202

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Nokia Customer Care Baseband Description and Troubleshooting

FM Radio

FM Radio

faults

Is the FM radio

working?

YES

Does the FM radio
produce a "Bong"

sound when

changing channels

(frequencies)?

YES

Check soldering

under C6100, R6101,

R6103, C6102. If not

working, then

change FM radio

chip (N6100).

NO

NO

END

Power on the phone

and turn FM radio on

by Phoenix

YES

Measure VFlash2

(VCCD/VCCA/

VCCVCO) at C6103/

C6116/C6117/L6101.

Is it 2.8V?

YES

Measure FM1=1.8V,

FM2=11 Khz,

FM3=1.8V, and

FM4=32 Khz. Is it

OK?

YES

Measure FMANT at

L6103. Is it 1.0V?

YES

FM

Radio

faults 2

NO

NO

Check solder on

NO

N6100, X101, and

replace N6100 if not

working.

NO

Check VFlash2 line

Change TikuEDGE

Check L6102, L6103,

C6104, C6109,
C6115, C2008,
C2009, C2010,

C2011. If OK, check

Tomahawk

connector (X2000)

on pin 11, 12, 13, 14

D2800

NO

(From
Radio

Faults 2)

NO

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FM Radio

faults 2

Measure VREF at
C6106. Is it 1.6V?

YES

Measure VAFL/VAFR

at C6180/C6182.

Does it have an

audio signal?

Retest

NO

NO

Check C6106

Change FM Radio

chip (N6100)

(To Radio

Faults 1)

YES

Is FM Radio

working?

YES

END

NO

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Camera

Camera

faults

Power on the phone

and turn camera on

by Phoenix or UI

menu

YES

NO

Make sure soldering
on D6600 and X6600

is OK and check

PUSL(1) on pin 19 of

X2451. Is it high?

YES

Check VDIG voltage

at C6615

YES

Check V2.8 voltage

at C6607

YES

Check whether CE is

high

NO

NO

NO

NO

Check D2200 and

replace it when

D2200 stays low

Try test again

Replace N6601

regulator

Replace N6600 if
there is no output
from the regulator

Check D2800 and

replace it if this

GenIO(27) is low all

the time

Bluetooth

See the RF Troubleshooting chapter for Bluetooth troubleshooting information. When
the flash D450 or UEME have been replaced the ESN has to be reprogrammed. This
automatically includes reprogramming the BT address.

SIM

The hardware of the SIM interface from the UEME (D2200) to the SIM connector (X2700)
can be tested without a SIM card. When the power is switched on, the mobile terminal
checks for a 1.8V SIM card and then a 3V SIM card. The mobile terminal attempts this
four times, whereafter it displays "Insert SIM card".

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The error "SIM card rejected" means that the ATR message received from the SIM card is
corrupted (e.g., data signal levels are wrong). The first data is always ATR, and it is sent
from the card to the mobile terminal.

SIM faults

Is the SIM a 3.0V or

1.8V card?

YES

Measure VSIM at

X2700 pin 3. Is it 3V

or 1.8V?

YES

Check SIM power-up

sequence. It should

look like the

following picture:

Replace used test

NO

Check SIM reader

NO

SIM card

X2700

If not as picture

VSIM

Measure VSIM at

C2203. Is it 3V?

YES

Replace R2700

NONO

UEME failure

Reset

Clock

Data

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Nokia Customer Care Baseband Description and Troubleshooting

GPS

GPS faults

Is VCORE at 1.5V?

YES

Is VIO at 1.8V?

YES

GPS_RF_CLK

(19.2MHz) OK?

YES

GPS_EN_RESET held

high?

YES

GPS_SLEEPCLK
(32.768KHz) OK?

YES

VRF_GPS OK?

YES

GPS_CLK (16.368MHz)

OK?

NO

NO

Troubleshoot CE

power supply

NO

Troubleshoot CE

VCTCXO circuit

If the BB ASIC is being

NO

held in reset,
troubleshoot the
source in the CE

Troubleshoot CE sleep

NO

NO

YES

NO

clock circuit

VRF_GPS regulator

enable line low?

Replace TCXO or GPS

RF ASIC

NO

Replace regulator

N052

YES

Test Mode 1 OK?

YES

CE sending code

download signals?

YES

SPI interface active?

YES

RF data and clock?

YES

Debug RF front end

NO

Replace GPS BB ASIC

Determine why CE not

NO

NO

NO

sending download

Replace GPS BB ASIC

Replace GPS RF ASIC

signals

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