Power Doesn't Stay On, Or Phone Is Jammed - Nokia NSE–3 SERIES Service Manual

NSE–3
Disassembly & Troubleshooting Instructions

Power doesn't stay on, or phone is jammed

If this kind of fault has come after flash programming, there are most
probably open pins in ICs.
The soldered joints of ICs: D200 (MAD2), D210 (FLASH), N100
(CCONT), D221 (SRAM) are useful to check at first.
Normally the power will be switched of by CCONT (N100) after 30 se-
conds, if the watchdog of the CCONT can not be served by software.
The watchdog updating can be seen by oscilloscope at pin 50 (DataselX)
of CCONT.
In normal case there is a short pulse from "1" –> 0 every 8 seconds.
The power off function of CCONT can be prevented by connecting a short
circuit wire from CCONT pin 29 to ground.
connect the shortcircuit fire from N100 pin 29 to ground (watchdog)
check C213, R213
YES
NO
J506 (RFC) 13 MHz
800 mV min
NO
check buffer V705 and
VCXO G600
Page 12
Power doesn't stay on or phone is jammed
YES
CCONT watchdog is served?
(pin 50 pulses 1 –> 0)
NO
OK
EEPROM (D240) pin 8 (VBB) 2.8 V
J522 (VXO) 2.8 V
YES
J227 master reset (Purx) = "1" (2.8 V)
YES
MAD2 (D200) pin 93: 13 MHz sine wave
clock signal: 500 mVpp min.
YES
Open pins or faulty circuit:
D200, D210, D221, N100
R215
Technical Documentation
software is able to run
check UI module
YES
If power is switched off
after few seconds, check
BSI and BTEM lines
NO YES
VBAT is correct
3.6 V
J228 sleep clock(SCLK)
NO
square wave 32 kHz
YES
Faulty circuit N100
or over loaded PurX line
Original, 11/97
PAMS
N100 is faulty
check sleep
NO
clock circuitry
(B100, R154...)