PAMS
Technical Documentation
NSC/W–1/3
Disassembly & Troubleshooting Instructions
Page 15
Original 11/99
Power doesn’t stay on or phone is jammed
EEPROM (D203) pin 8 (VBB) 2.8 V
G850 pin 3
NO
YES
TP 18 master reset (Purx) = ”1”(2.8 V)
NO
TP 20 sleep clock(SCLK)
square wave 32 kHz
NO
YES
Faulty circuit N150
or over loaded PurX line
check sleep
clock circuitry
(B150, R156..)
YES
YES
NO
TP 23 19.44 MHz sine
YES
check R272
NO
check buffer V850 and
VCXO G850
YES
connect the shortcircuit fire from N150 pin 29 to ground (watchdog)
N150 is faulty
OK
VBAT is correct
3.6 V
YES
CCONT watchdog is served?
(pin 50 pulses 1 –> 0)
NO
YES
software is able to run
check UI module
after few seconds, check
BSI and BTEM lines
If power is switched off
Open pins or faulty circuit:
D202, D200, D201, N150
R212
wave 500 mV min
TP 23 (N250) pin 2: 19.44 MHz sine wave
Clock signal: 500 mV Vpp typ.
TP24 (N250) pin 63: 9.72 MHz Square wave
clock signal 2.80 Vpp