Nokia 9000i Service Manual page 267

After Sales
Technical Documentation
3.1 LCD ON?
The first step is to check whether the LCD is on when in testmode. When
the PDA boots, and if the testmode pin is active, the CPU controls the
LCD on. If the LCD remains blank, then proceed to 3.1.1. If the LCD is set
on, then more detailed tests can be carried out when proceeding to 3.2
3.1.1 Disconnect UI Flex
In order to isolate the problems in the LCD module, disconnect the UI flex
from the PDA. Of course it can be easily tested if the problem disappears
when connecting a working LCD module to the PDA.
If the problem can be isolated to the PDA module, then proceed to 3.1.2
3.1.2 LCDVCC OK
Check if the LCDVCC is within it's legal limits 4.5V..4.8V. If not, then
proceed to 3.1.2.1. If yes, then go to 3.1.3
3.1.2.1 LCDVCCON active
If the LCDVCCON is active (high) but the LCDVCC level is out of the limits
then proceed to 3.1.3.2. If the CPU does not control the LCDVCCON
active, then go to 3.1.2.2
3.1.2.2 CPU Fault
If the CPU does not control either the LCDVCCON or / and the
LCDVEEON, and the signals are not forced low in the PDA power unit,
then the CPU is defective.
3.1.3 LCDVEE OK?
Check if the LCDVEE is within it's legal limits 19V..23V. If not, then
proceed to 3.1.3.1. If yes, then go to 3.1.4
3.1.3.1 LCDVEEON Active?
If the LCDVEEON is active (high) but the LCDVEE level is out of the limits
then proceed to 3.1.3.2 If the CPU does not control the LCDVCCON
active, then go to 3.1.2.2
3.1.3.2 Check PDA Power Unit
If the CPU controls the LCDVCCON active, but the LCDVCC is out of the
limits, check the PDA power unit. Check components V80, V86, R81, R72
and C91.
In a case that the CPU controls the LCDVEEON active, but the LCDVEE
is out of the limits, check the PDA power unit. If voltage at positive
terminal of C89 is not between 20V and 24V go to PDA power unit
complete check to 3.1.1. Check V84, R75, R76 and R96. There must be
4.1V voltage difference over V84. If OK check that N83 pin 4 is in low
Original, 05/97
RAE/RAK–1N
Faultfinding/Disassembly
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