Nokia 1508 User manual

1508(RM-388)
Baseband Description and Troubleshooting
Nokia Customer Care
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Copyright © 2008 Nokia, All rights reserved
Nokia Customer Care
1508 (RM-388)
Mobile Terminal
Baseband Description and Troubleshooting

1508(RM-388)
Baseband Description and Troubleshooting
Nokia Customer
Care
Issue 1
Copyright © 2008 Nokia, All rights reserved
Contents
BB Troubleshooting 1508

1508(RM-388)
Baseband Description and Troubleshooting
Nokia Customer
Care
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Copyright © 2008 Nokia, All rights reserved
1508 system brief introduction
1508 main features
1508 is a CDMA phone based on the VIA platform.
1) CDMA Cellular support only
2) FM stereo radio
3) Compliance to USB 2.0 (full speed)
4) R-UIM card
The main devices
Device Model number Supplier
Baseband processor CBP 5.6 VIA
PMU ACT5805 Active
Memory S71GL064NB0BFW0Z0 SPANSION
LCD BYD4205T BYD
FM Stereo radio Si4702-B16-GM SILICON LABS

1508(RM-388)
Baseband Description and Troubleshooting
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Copyright © 2008 Nokia, All rights reserved
Figure 1 Component layout (Bottom)

1508(RM-388)
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System Block Diagram
System Description
1508 is a CDMA (Cellular band) Mobile Phone. The phone supports:
- forward and reverse link data rates of up to 153.6kbps.
- 4GV vocoder
- 1.47”(128*128) CSTN LCD
- Stereo FM radio
Platform Introduction
CBP 5.6
VIA Telecom’s CBP 5.6 single-chip CDMA Base Band Processors
provide a complete 3G CDMA2000® 1X (Release 0) solution. They
are designed to meet or exceed the specifications of mobile stations
for worldwide 3G CDMA systems as specified by CDMA2000® 1X
(Release 0) standards and are backward-compatible to IS -95.
CBP 5.6 integrates three processor subsystems

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ARM7TDMI® Control Processor (CP) supports the protocol stack,
user interface, and hardware interface processing. Two TeakLite®
Digital Signal Processors (DSPs): one DSP supports CDMA modem
processing, the second DSP supports CDMA voice processing
The main features of the CBP 5.6
zSupports CDMA2000® 1X (Release 0)
zBackward compatible to IS-95 standards
zSupports IS-2000 Quick Paging Channel for improved standby time
zSupport for multiple CDMA band classes (Band Class 0/US-Cellular, Band Class
1/US-PCS, Band Class 3/JTACS, Band Class 4/Korean-PCS); support for
additional band classes which can be added upon customer request
zSpecial purpose logic provides signal processing, modulation, demodulation,
hardware accelerators and interfaces for keypad and display
zMixed signal circuitry for the Rx analog-to-digital converter (ADC), Rx filter, Tx
digital-to-analog converter (DAC), Tx filter, internal PLLs, voice codec, auxiliary
ADCs, auxiliary DACs, RF control and 32.768 kHz oscillator
zSupport for forward and reverse link data rates of up to 153.6 kbps (CBP5.6
only).
zDual supply voltage (1.8 V digital core, 3.0 V analog and 3.0 V digital I/O)
z3.0 V or 1.8 V external memory interface
zUSB support (12 Mbps)
zRemovable User Identity Module (R-UIM) compliant with IS-820
z32-voice polyphonic ringer

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The interface of the CBP5.6 is described in the following diagram.
Receive and transmit interfaces for CBP 5.6 provide analog I and Q
signals and support super-heterodyne radio and direct conversion
radio design. The CP external-memory interface supports 3.0V or
1.8V, the address bus supports 16-bit address which can support
three to six external devices via chip selects. CBP 5.6 includes 48
GPIOs and interrupts, some of which are multiplexed with other
functions. All GPIO pins are in input state by default and use a large
pull-up or pull-down resistor value to minimize the current drain. The
USB port supports data rates of up to 12Mbps, the USB analog
drivers and 48.00MHz PLL are integrated into CBP 5.6, the control
processor manages the USB function. Two independent serial-
peripheral interfaces are provided on CBP 5.6: one is for RF control
and the other is for general-purpose use. The R-UIM interface
supports 3V UIM cards and consists of five pins, these pins are
multiplexed with another function. The CP manages the R-UIM
function.
Five independent PDM DACs are supplied on the CBP 5.6 chip.
Three of the outputs are dedicated to radio-control signals for Rx
automatic gain control (AGC), Tx AGC, and automatic frequency
control (AFC). The fourth and fifth PDM outputs are spares. The
PDMs are 12-bit DACs and have a guaranteed output range of 0.2 V
to 2.5 V.
The 12-bit auxiliary ADC supports eight independent external
channels on pins AUXADC [7:0]. There are also eight internal
channels used to measure internal analog voltages. The input
voltage range is 0.2 V to 2.7 V. The conversion time is 156 µsec. The
typical uses of the external auxiliary ADC channels include: Tx RF
power measurement, battery voltage, and temperature sensors.
The baseband is powered by the following PMU ACT5805 regulators:
VDD_DIG = 3.0v
VDD_CORE = 1.8v
VDD_TXPLL = 2.85v
VDD_TCXO = 2.85v

1508(RM-388)
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VDD_ANALOG =3.0v
VDD_RX = 2.85v
VDD_TX = 2.85v
VIB_P= 2.8v~3.6v
Figure 1 Component layout (Bottom)

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Power Up
The mobile terminal uses the power key and a charger to power up.
Power Key
When the power key is pressed, the PMU enters the power-up sequence. Pressing the
power key causes the POWER_ON pin to VBAT. The POWER_ON signal is not part of
the keypad matrix. The power key is connected to the PM. This means that when the
power key is pressed, an interrupt will be generated to the CBP in order to power on the
CBP. The CBP reads the PMU IC’s interrupt register and notifies that it is a
KPADPWR_N interrupt. The CBP reads the status of the POWER_ON signal using the
PMU’s (I2C) control bus. If the POWER_ON signal stays High for a certain time, the CBP
accepts this as a valid power-on state and continues with the software baseband
initialization. If the power key does not indicate a valid power-on situation, the CBP
powers off the baseband.
Charger
Charging is controlled by start-up charging circuitry in order to detect and start charging
in case the main battery is not full and the PMU has no supply.
Power Off
While the PS_HOLD signal from the CBP is high, and the PMU IC is in power-on
status. The PMU continually monitors three events that could trigger a power-off
sequence:
zThe CBP drives the PS_HOLD signal low responding to the pressing of the
keypad power button.
zBattery voltage drops below power off threshold (Battery Voltage < 3.2 V).
zThe PMU IC die temperature exceeds its “severe” over-temperature threshold.
Clock Distribution
The CBP derives its internal clock from two clock inputs, VC-TCXO and SLEEP_CLK.
The main clock signal for the baseband is generated from TCXO.

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(Temperature-compensated crystal oscillator) The CBP’s TCXO clock input supports
the frequency 19.2 MHz +/-2ppm. An integrated PLL and digital divider inside the
CBP are used to create the required clock for the system.
The SLEEP_CLK provides a 32.768 kHz +/-20ppm clock source to drive the CBP
controller into sleep mode. At this mode, most of the CBP is powered down and the
TCXO is disabled.
Power Distribution
In normal operation, the baseband is powered by the mobile terminal‘s battery pack.
The battery pack consists of one lithium-ion cell with a capacity of 860 mA and safety
and protection circuits
The PMU ACT5805 IC controls the power distribution for the whole mobile terminal,
which includes the baseband and the RF regulators, but excludes the RF power
amplifier (RF PA) which drains power from the battery directly. The battery provides
power directly to the following parts of the system:
· PMU ACT5805
· RF PA
· Vibrator
· Keyboard & LCD backlights
· Audio Amplifier
The heart of the power distribution is the power control block inside the PMU
ACT5805. It includes all the voltage regulators and feeds the power to the entire
system. The PMU ACT5805 handles hardware power-up functions so that the
regulators are not powered on and the power up reset (NRST) is not released if the
battery voltage is less than 3.2V.
The baseband is powered by the following PMU ACT5805 regulators:
Regulator Voltage
Rating
Current Notes

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VDD_DIG 3V 250mA
Always enabled except during power-off
mode
VDD_CORE 1.8V 150mA
Enabled only when the system is powered
on (Off during sleep and power-off modes)
VDD_TXPLL 3.0V 80mA Enabled only when the transmitter is on
VDD_TXXO 2.8V 80mA
Enabled only when the system is powered
on (Off during sleep and power-off modes)
KEYPAD_LED 2.8V 100mA
Enabled when the system is powered on, or
the keys are pressed, etc.
VDD_RX 2.85V 80mA Enabled when the receiver is on
VDD_TX 2.85V 150mA Enabled when the transmitter is on
VDD_VIBE 3.0V 150mA
Enabled only when the system is powered
on (Off during sleep and power-off modes)
VC-TCXO
The CBP device integrates a phase-locked loop from the TCXO clock input.
The PMU optimizes TCXO operation that enables and disables appropriate circuits in
the proper sequence. The controller is enabled by the OSC_EN signal from the CBP.
When the selected transition occurs at OSC_EN, the controller quickly enables the
TCXO regulator and the input buffer, and begins counting SLEEP_CLK pulses.
Within an initial power on period, the TCXO will be stabilized to its own calibrated
frequency. This initial period, in units of 32.768 kHz clock pulses, is programmed into
a timer within the controller. When the timer expires, the output buffer is enabled. It
synchronizes with the TCXO input such that the TCXO_OUT signal is glitch free, only
valid TCXO pulses are output.
SLEEP Crystal Circuit for 32.768 kHz
The 32.768 kHz crystal oscillator is the primary SLEEP clock source when TCXO

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clocks are disabled to save power.
Charging Operation
Battery
The 1508 uses a Lithium-Ion cell battery with a capacity of 860mA.CBP reads the
resistor inside the battery pack on the BSI line to identify the battery size. Different
charging algorithm will be used for different battery sizes. The resistors are
connected to the BSI pin inside the battery connector.
BSI= BATT_DET
Charging Circuitry

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Display and Keypad
The mobile terminal uses light-emitting diodes (LEDs) for liquid crystal display (LCD)
and keypad illumination. There are two white LEDs for the LCD and two LEDs for the
keypad. KEYPAD_LED is the signal used to drive keypad LEDs. LCD_BL_EN is the
signal used to drive LCD LEDs. The mobile terminal uses a color LCD. The interface
uses a parallel bus to transfer the Command/ Data between CBP and LCD.
Troubleshooting
First, carry out a thorough visual check of the module. Make sure in particular that:
• There is no mechanical damage.
• Soldered joints are OK.
• ASIC orientations are OK.
The following hints should help find the cause of the problem when the circuitry
seems to be faulty. Troubleshooting instructions are divided into the following
sections:
• ‘Power Does Not Stay ON’
• “Charger Faults’
• ‘Audio Faults’
• ‘Display Faults’
• ‘Keypad Faults’
•‘No Vibration’
•‘Series/USB Interface Disabled’
•‘UIM Card Unreadable’
Note:
• CBP5.6 is underfilled and can not be replaced.
• The Shielding Case Assy can not be reused after removal.
• After using the heatgun, the domesheet needs to be replaced.

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Repair Function in can not Power-on Status (refer to
PMU Circuit)
•The current status resulting ‘Power Off” could be divided into three cases: Big
current, no current, no holding current.
Case One.
Big current appears when power is fed to Vbattery or “power on” key is pressed
on the handset.
Check if the following voltages of PMU are normal: VBAT, VDD_DIG,
VDD_CORE, VDD_TXPLL, VDD_TCXO, VDD_RX, VDD_TX,
If the voltages are abnormal, check the fault reason..
Case Two.
If current is zero, check CN703and C1011,C1012,C1013,C1014,C1015,C1016.If
there is no power output, PMU is defective. Phone cannot be repaired and must
be replaced.
Case Three.
•Raise the voltage of PS-HOLD, and measure every output voltage of PMU, The
reference clock Power-on needed is KHZ.19.2MHZ etc.
such as :VDD_DIG,VDD_CORE,VDD_TXPLL,VDD_TCXO,VDD_RX,VDD_TX ;
•Check if the clock TCXO（19.2MHz）and RTC（32.768KHz）are normal.
•If the signals are abnormal, please check the fault reason;
•If it is normal, please check the welding of CPU and Flash and perform welding or
replacement. (Replacement includes Flash Updating).The welding of the display
panel connector should also be checked, because the shortcut of the parallel
data signal and Read & Write signal on the display panel connector will lead to
failure of CPU in invoking the programs of FLASH.

1508(RM-388)
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Power Does Not Stay ON Troubleshooting

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PMUACT5805 circuits

1508(RM-388)
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No Sound in Earpiece & Microphone Check (refer to MIC
headset, Audio PA Circuit design)
Enter the test mode ’LoopBack’ by pressing test order #0000# then press ‘calling
key’ when the No Sound in Earpiece & Microphone message appears.
1. If the test result is normal, it indicates that the ‘Loopback’ circuit (receiver &
microphone) is OK in hardware connection; the bottom socket should be checked
whether it has been short circuited to the ground; If it is grounded, the mobile phone
software will detect that the earpiece is in the Insert Mode, which sets the mobile
phone in earpiece mode, and it means both of the earpiece and the microphone do
not work.
2. If the test result shows that the ‘Loopback’ is abnormal, the fault reason should
be picked up from the earpiece and the microphone. Dial 112 emergency call and
diagnose fault.
If the sound works, the microphone Mic is directed wrong, or it indicates the
receiver does not work properly.
3. In the case the Contact Connection is adopted between the earpiece and the Mic
of the mobile phone, test if the connection works.
•If there is a fault in telephone receiver, first try to recover the earpiece by
performing the experiment described above. If it still doesn’t work, Audio PA chip
or CPU chips may be damaged from poor welding or injury. The chips should
then be repaired by re-welding or replacement.
•If there is a fault in Microphone, first try to recover the earpiece by performing the
experiment described above. If it still doesn’t work, Audio PA chip or CPU chips
may be damaged from poor welding or injury. T The chips should then be
repaired by re-welding or replacement.

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Audio Faults Troubleshooting

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1508(RM-388)
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MIC Circuit Design
Headset Circuitry