NSW-5
Disassembly and Troubleshooting Instructions
PAMS Technical Documentation
Page 19
Issue 1 10/00
Nokia Mobile Phones Ltd.
3. 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 solder joints of ICs MAD1 (D202), Flash
(D201), and SRAM (D200) are to be checked at the extent possible (by
microscope from the side of PWB and lightly pressing components while
switching power on).
Normally the power will be switched off by CCONT (N150) after 32 se-
conds, if the watchdog of the CCONT can not be served by software. The
watchdog updating can be seen by oscilloscope at CCONT’s J154 (Data-
selX). In normal case there is a short pulse from ”1” –> ”0” every 8 se-
conds. The power off function can be prevented by connecting a short cir-
cuit wire from WDDIS (CCONT E4 (J150)) to ground (J156).
Power does not stay on or is jammed
FLASH (D201) VBB is 2.8V (C203)
NO
YES
PURX (J152) master reset = ”1” (2.8 V)
NO Sleep clock SLCLK
J157 square wave 32 kHz
NO
YES
Faulty circuit N150
or over loaded PURX line
check sleep
clock circuitry
(B150, R157...)
YES
YES
Check buffer V850 and
YES
Connect short circuit wire from
N150 is faulty
OK
VBAT is correct
3.6 V
YES
CCONT (N150) watchdog is served?
J154 pulses 1 –> 0)
NO
YES
Software is able to run
check UI module
after few seconds, check
BSI (X104:1 to C173) and
BTEMP (X105:2 to C174)
lines
If power is switched off
Open pins or faulty circuit:
D202, D200, D201, N150
RFC (J250) 19.44 MHz sine wave
Clock signal: 700 mV Vpp typ.
COBBACLK (J251) 9.72 MHz square wave
clock signal 2.80 Vpp
Watchdog J150 to ground J156
VCXO G850
NO
Figure 3. Troubleshooting diagram in case the phone does not stay on or
is jammed.
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