Nokia Mobile Phones NSE-5 Series Service Manual page 232

NSE–5
Troubleshooting
Check if fault information from
Prommer is one of the following:
a) MCU doesn't boot
b) serial dataline failure
c) serial clock line failure
failure is one of the
above mentioned?
Yes
Connect watchdog
disable (WDDIS R413
end towards edge) to
GND.
C308 end towards RTC–battery
(Vbb) is 2.8V
C112 end towards bottom (VXO)
is 2.8V
C
Master RESET (PURX
R147 towards board)) is "1"
(2.8V) after ca. 60ms
Yes
13MHz clock
D700 pin 4
Yes
500mVpp min.
Check R727, V702,
B R728, R714, G701
Figure 2.
Page 6
No
A
No
See section "Phone is
totally dead".
Yes
No
Check sleep clock
(C150 end towards MAD)
32kHz square wave
No
RFC 13MHz
No 800mV min.
V702 collector
Technical Documentation
FLASH Programming
doesn't work.
Check WDDIS line:
X201 pin 11 –> R413 end towards edge
and
R413 other end –> X400 pin 7
Line OK?
Yes
Faulty PCB
Check sleep clock circuit.
R117, R118, R121, R135,
C103, C104, C149, B100
No
and C150
Yes
Faulty N100 or
overloaded PURX line
Yes
Check D700
PAMS
No
Issue 1 07/99