Nokia 9000i Service Manual page 256

RAE/RAK–1N
Faultfinding/Disassembly
PDA Power Unit Check
4.
NO
Undervoltage lockout
UVLO
fault
11. NO
Replace
D80
25. NO
Check
V80, V86
27. NO
Check
N80, C80
29. NO
Check
G87, V85
Page 8 – 14
3.
YES
removed?
YES
5.
NO
Check Vsys
Vsys
regulator.
OK?
YES
10.
Reset
OK?
YES
12.
NO
LCDVEE
OK?
YES
24.
Is 0V applied to
LCDVCC
OK?
YES
26.
VCC5
OK?
YES
voltage toggling?
28.
VBACK
OK?
YES
Is there valid bias
voltage at C89 plus
Power Unit
OK!
Check V87, V82
Technical Documentation
0.
Start
1.
NO
Input filter
OK?
6. 7.
Is N81 pin 7
toggling?
YES
9.
Check V88,
L82, C84
13.
NO
Is LCDVEEON
Command
enabled?
LCDVEE on.
YES
15.
NO
Check N82,
N83 pin 4?
R75, R76, R96
YES
17.
NO
Is N83 pin 1
toggling?
controller fault
YES
19.
NO
Is V89 anode
Check L81, V81,
R77, R74, R85
YES
21.
NO
Check V89, C89
and feedback
terminal?
YES
23.
R95, R98, R94
After Sales
2.
Input filter
fault
8.
NO
Vsys controller
fault
14.
16.
18.
LCDVEE
20.
22.
resistors
Original, 05/97