Nokia 5110 Service Manual

PAMS

Technical Documentation

NSE–1

Disassembly & Troubleshooting Instructions

Page 8

Original  03/98

Flash programming doesn’t work

EEPROM (D240) pin 8 (VBB) 2.8 V

J522 (VXO) 2.8 V

NO

YES

J227 master reset (Purx) = ”1” (2.8 V)

NO

J228 sleep clock(SCLK) 

square wave 32 kHz

NO

YES

Faulty circuit N100

or over loaded PurX line

check sleep

clock circuitry

(B100, R154...)

YES

MAD2 (D200) pin 93: 13 MHz sine wave

clock signal: 500 mVpp min.

YES

NO

J506 (RFC) 13 MHz

800 mV min

YES

check C213, R213

NO

check buffer V705 and

VCXO G600

Check that following lines are correct:

YES

If the fault information from the prommer is:

b) serial data line failure

a) MCU doesn’t boot

c) serial clock line failure

connect:

FCLK (MBUS) line: X100 pin 11 –> D200 pin 112

FTX (fbus_tx) line: X100 pin 13 –> D200 pin 104

FRX (fbus_rx) line: X100 pin 12 –> D200 pin 109

check also pullup and pulldown resistors: R203, R201, R215

OK

GND : X100 pin 14 –> GND

connect the shortcircuit fire from N100 pin 29 to ground (watchdog)

N100 is faulty

OK

 

Enable the selftest function of D200 by connecting

shortcircuit between testpoints J229 and J230

Connect an oscilloscope to testpoint J225 and switch 

power on

Voltage level rises to ”1” after power on at testpoint J225

NO

YES

There is a shortcircuit

somewhere in memory control

lines or MCU address lines or

MCU lower (7:0) data lines

There could be open pins in circuits D200 (D211, D240)

If not, the PCB or D200  (D211, D240) is faulty

VBAT is correct

3.6 V

YES