Nokia 9000i Service Manual page 283

After Sales
Technical Documentation
8.2.1 CPU Fault
If either of the tests in the local loop mode fails, then the CPU is defective.
8.3 Test COM2 in Local Loop
Select the COM2 to be tested in the local loop. The test is ran at 9600
baud by default.
8.4 Test Successful?
If the test passes successfully proceed to 8.5, otherwise branch to 8.2.1
8.5 Connect RBUSRXD and RBUSTXD Together
In order to test the external lines of the COM2, the RBUSRXD and
RBUSTXD may be connected together e.g. in the board–to–board
connector. When testing the COM2 in this external loop, the bytes are
received via this connection.
8.6 Test COM2 in External Loop
Choose in the service software the COM2 test in external loop.
8.7 Test Successful?
If the test passes in the external loop, the serial ports can be considered
to be functional, otherwise continue to 8.7.1
8.7.1 R947 OK?
There is only one resistor between the CPU pins 97–98, check it along
with the connections. If OK, go to 8.2.1, if not go to 8.7.1.1.
8.7.1.1 Change Resistor
Change the faulty R974.
Original, 05/97
RAE/RAK–1N
Faultfinding/Disassembly
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