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PAMS
Technical Documentation
NSE–6
Disassembly & Troubleshooting Instructions
Page 13
Original 08/98
Power doesn’t stay on, or phone is jammed
If this kind of fault has come after flash programming, there are most
probably open joints in ICs. The solder joints of ICs: MAD2 (D200), Flash
(D220) and SRAM (D230) are to be checked at the extent possible (by
microscope from the side of PCB and lightly pressing components while
switching power on).
Normally the power will be switched off by CCONT (N100) after 30 se-
conds if the watchdog of the CCONT can not be served by software. This
updating can be seen with an oscilloscope at CCONTCSX (J236). In nor-
mal case there is a short pulse from “1” to “0” every 8 seconds. The pow-
er off function can be prevented by connecting WDDIS (J111) to ground.
Power doesn’t stay on or phone is jammed
CCONT watchdog is served?
(J236 pulses 1 ––> 0 every 8 sec)
Connect J111 (WDDIS) to GND
VBB (C107 upper side) 2.8 V
VXO (C149 upper side) 2.8 V
Software is able to run
If power is switched off after
few seconds, check BSI and
BTEMP lines
Master reset PURX (J227) 2.8 V
RfClk (R213 lower side) 13 MHz sine wave
clock signal: 500 mVpp min
Open pins or faulty circuit:
D200, D220, D230, N100, R215
VBAT is 3.6 V
N100 faulty
Sleep clock SCLK (J228)
square wave 32 kHz
Check sleep clock
circuitry (B101, R154..)
RFC (C664) 13 MHz
800 mV min
Check C213, R213
Check buffer V660
and VCTCXO G660
N100 faulty or
overloaded PurX line
YES
NO
YES
OK
NO
YES
YES
YES
YES
YES
NO
NO
NO
NO
YES
Flashing can give information in deciding
which IC to change. Changed Flash ID
for example indicates Flash failure