Nokia NKC-1X Series Guide

CCS Technical Documentation
NKC-1X Series Transceivers
Issue 1 02/03 Nokia Corporation
Troubleshooting Instructions

NKC-1X
Troubleshooting Instructions CCS Technical Documentation
Page 2 Nokia Corporation Issue 1 02/03
Table of Contents
Page No
Transceiver Troubleshooting ......................................................................................... 4
Baseband Troubleshooting ..........................................................................................4
General about testing................................................................................................. 4
Troubleshooting ........................................................................................................ 4
Power up faults.......................................................................................................... 5
Flash Programming does not work.......................................................................... 10
Charging .................................................................................................................. 12
Audio failures.......................................................................................................... 13
Accessory detection................................................................................................. 15
Sleep Clock ............................................................................................................. 16
Display/Keyboard lights do not work ..................................................................... 18
Display does not work............................................................................................. 19
Buzzer does not work.............................................................................................. 20
Keyboard does not work ......................................................................................... 20
Receiver Troubleshooting ..........................................................................................21
General instructions for RX troubleshooting .......................................................... 21
Path of the received signal ...................................................................................... 21
Fault finding charts for receiver chain .................................................................... 21
Transmitter Troubleshooting .....................................................................................25
General instructions for TX troubleshooting .......................................................... 25
Path of the transmitted signall................................................................................. 25
Fault finding charts for the transmitter.................................................................... 25
Synthesizer Troubleshooting .....................................................................................29
19.44 MHz reference oscillator ............................................................................... 29
RX VHF .................................................................................................................. 31
TX VHF................................................................................................................... 32
UHF SYNTHESIZER ............................................................................................. 33

CCS Technical Documentation Troubleshooting Instructions
NKC-1X
Issue 1 02/03 Nokia Corporation Page 3
List of Figures
Page No
Fig 1 Power up sequence .....................................................................................................7
Fig 2 Fault tree, phone does not power up...........................................................................9
Fig 3 Fault tree, charging .....................................................................................................13
Fig 4 Fault tree, earpiece fail ...............................................................................................14
Fig 5 Fault tree, microphone fail .........................................................................................15
Fig 6 Fault tree, accessory detection....................................................................................16
Fig 7 Fault tree, sleep clock .................................................................................................17
Fig 8 Fault tree, Display/Keyboard lights............................................................................18
Fig 9 Fault tree, Display does not work...............................................................................19
Fig 10 Fault tree. AMPS ......................................................................................................22
Fig 11 Fault tree. Transmitter troubleshooting ....................................................................26
Fig 12 Fault tree: Power control loop ..................................................................................28
Fig 13 Detected voltage levels.............................................................................................29
Fig 14 Fault tree: 19.44 MHz oscillator...............................................................................30
Fig 15 Fault tree: RX VHF VCO.........................................................................................31
Fig 16 Fault tree: TX VHF VCO .........................................................................................32
Fig 17 Fault tree: UHF Synthesizer .....................................................................................33

NKC-1X
Troubleshooting Instructions CCS Technical Documentation
Page 4 Nokia Corporation Issue 1 02/03
Transceiver Troubleshooting
The first thing to do when you are encountered with a problem is to carry out a thorough
visual check of the module. Make sure that:
• there are no mechanical damages
• the solder joints are OK
Note: Before changing anything, ALL SUPPLY VOLTAGES AND THE SYSTEM
CLOCK / SLEEP CLOCK should be checked.
Baseband Troubleshooting
General about testing
The phone has three different modes for testing and/or repairing the phone. The modes
can be selected with suitable resistors connected to BSI- and BTEMP- lines as illustrated
in the table below:
If the corresponding resistors are connected, the MCU software automatically enters into
the local or test mode when the supply voltage is connected to the phone.
The power can be switched on by:
1 Pressing the power key.
2 Connecting the local/test mode resistors to the bsi/btemp lines and connecting
the battery voltage to the phone.
3 Connecting a charger.
4 Phone’s internal functions (Real time clock alarm)
In the local and test mode, the baseband can be controlled through MBUS or FBUS (FBUS
is recommended) connections using Phoenix service software.
Troubleshooting
Note: Most of the baseband repair actions require removing the baseband shield.
The shield must not be removed unless separately authorized by the program.
Table 1: Phone operating mode
Mode BSI-resistor BTEMP resistor Remarks
Normal 68k 47k
Local 560_
(<1k_)
Whatever
Test > 1k 560_ (<1k_) Recommended for baseband testing. Same as local
mode, but making a phone call is possible.

CCS Technical Documentation Troubleshooting Instructions
NKC-1X
Issue 1 02/03 Nokia Corporation Page 5
Note: The phone’s ESN has to re-written to the UEM, if the UEM is replaced. This
can be done only in Central Service.
The BB troubleshooting instructions consist of the following topics:
1Powerup
2 Flash programming
3Audio
• Earpiece
• Microphone
4 Charging
5 Accessory detection
6Sleepclock
7 User interface
• Display
• Lights
• Buzzer
• Keyboard
Power up faults
Power up sequence
1 The UEM acts as a HW master during start up
• Vbatt limits: 2.1V for internal state machine, 3V triggering whole startup
• Regulator sequencing
• HW "core" regulators "on": Vio, Vcore, VR3, Vflash1
• These regulators supply the processors, memory, chip interfaces and clock
source in RF
• Reset releasing delay
• Supply voltages stabilize to their UEM HW default values

NKC-1X
Troubleshooting Instructions CCS Technical Documentation
Page 6 Nokia Corporation Issue 1 02/03
• RFCLK grows to full swing
• The core is ready to run but waiting for the PURX release
• Reset releasing
• The UPP releases the SLEEPX up to the "non sleep" -state to prevent the
UEM switching the regulators "OFF"
2 MCU starts running the Bootsrap Code
• written in stone/ UPP internal ROM
• the program checks if there is any reason for the FDL mode (Flash Down
Load)
• If there is an executable code in FLASH and there is no reason for FDL, the
MCU starts running the MCU program from FLASH.
3 MCU runs the FLASH MCU code
• the phone initialization, user interfaces, internal blocks etc.
• Core regulator voltage setting for required DSP speed
• Initializes the DSP and concerning HW
• Releases DSP reset -> DSP starts running
Note: In figure below, the RF_Clk frequency appears to be lower than 19.44MHz
because of a too low oscilloscope sampling frequency (2kS/s).

CCS Technical Documentation Troubleshooting Instructions
NKC-1X
Issue 1 02/03 Nokia Corporation Page 7
Figure 1: Power up sequence
Figure 2: Power up sequence
1 Power key pressed
•After 20ms UEM enters RESET MODE if VBAT>Vmstr+
•VFLASH1, Vana, Vcore, Vio and VR3 goes high.
•VCTCXO enabled by VR3 -> RFClk 19.44 MHz running.
2 Purx released
•Purx released by UEM, UEMINT goes high for 100 ms, SleepX goes high and UEM
starts feeding SleepClk (32 KHz) to UPP.
Note: The sleepclock starts running in the crystal circuitry (B200) immediately when
the battery voltage is supplied.
3 Software running
•Default value for Vcore is 1.5 volts when the software is running.
•Cbus (1.08MHz) clock starts running.

NKC-1X
Troubleshooting Instructions CCS Technical Documentation
Page 8 Nokia Corporation Issue 1 02/03
Phone does not start up normally or does not stay on
Note: In case of power up faults, it is not possible to force the phone on by disabling
the watchdog. Instead, measurements should be taken immediately when the
power key is pressed or when the battery voltage is connected to the phone
(local/test mode).
The easiest way to check if the software is running when the phone takes an abnormal
amount of current is to measure the cbusclk and Vcore.
The Dbus clock (programmable 9.72MHz) is not automatically visible in the test and local
modes.

CCS Technical Documentation Troubleshooting Instructions
NKC-1X
Issue 1 02/03 Nokia Corporation Page 9
Figure 3: Fault tree, phone does not power up
Try to start phone to
test or local mode
Check the
power key
Check X101
Measure
Vflash1,Vana,Vio,Vcore
,VR3when pwr key
pressed
Check 19.44MHz
RF-clock from C420
Check that purx
goes up to 1.8V
Change UPP
(D400)
Change the
UEM (D200)
OK
Measure VBAT
from C261
Check R202,
R205, C217,
C220
Check G790
(missing,
misaligned)
Measure
J406. Should
be 1.08 MHz
Check
C420
Check
19.44MHz from
G790
Change N801
FAIL
Re-flash phone
OK
OK
FAIL
VANA & VR3
missing
FAIL
OK
OK
OK
Check
R792,C792,
C793
Change
G790
OK
FAIL
FAIL
OK
OK
FAIL
OK
OK
OK
FAIL
Programmng ok,
but phone doesn't
start
Go to flash failure
chart
Programming
fails
R206, R207,
C220, C240

NKC-1X
Troubleshooting Instructions CCS Technical Documentation
Page 10 Nokia Corporation Issue 1 02/03
Flash Programming does not work
Flash programming procedure
1 The phone communicates with the prommer via the production test pattern,
using the following signals:
• FBUSTX(serial data to phone)
• FBUSRX(serial data from phone)
• MBUS(serial clock for FBUSRX)
• VPP(External flashing voltage for speed up flashing)
• The BSI line is also used when initializing flashing (battery connector).
2 When the phone is powered (VBAT>3V), the MBUS and FBUSTX lines are pulled
up internally by the phone.
3 The prommer sends a command to the UEM, using FBUSRX, to enter the Flash-
mode. During the sending of this command, the prommer keeps the BSI line high
and MBUS is used as a serial clock.
4 When the Flash-mode command is acknowledged, UEM enters the Flash-mode
and releases reset (PURX) to MCU.
5 After reset is released, UPP checks if there is a request for the Bootstrap code
(that resides in the UPP ROM).
6 The request for Bootstrap is the MBUS pulled down by the prommer (if the boot-
strap is not requested, the bootstrap code jumps to FLASH SW).
7 If the Bootstrap code is requested, UPP enters the Flash-mode and sets FbusTX to
'0' as an acknowledgement to the prommer. This is an indication that UPP can
run, at least, the fixed Bootstrap code – although it is not able to run the FLASH
code. UPP then sends an UPP-ID to the prommer via the FBUSTX line.
8 After the prommer has received the UPP-ID, it sends a corresponding Secondary
Boot Code to the phone via FBUSRX. The Secondary Boot Code, when run in UPP,
requests UPP to send information to the prommer about the flash type and other
HW-related parameters about the device to be flashed.
9 Prommer then sends the Algorithm Code corresponding to the HW parameters,
and this algorithm, when run in UPP, takes over handling the MCUSW transfer to
Flash.
10 12 volts can be supplied to Vpp (by the prommer) to speedup flashing.