Nokia 9000i Service Manual page 263

After Sales
Technical Documentation
1.4 Check Buzzer Connections
In the case of POST found error, the PDA can beep an error code. The list
of the possibly error codes can be found in the appendix A. In order to
hear the possible beeps, the connection from the CPU (D130) pin124 to
the buzzer must be functional, i.e. the SIM flex should be connected to the
CMT, and the PDA–CMT connection must carry a BUZZEROUT signal.
The beeps can be also seen using a scope connected to the CPU, pin
124, where the beeps generate a square wave. If the signal can be seen
but no sound is heard, then check the circuitry R142–R148, V132–V135,
C138, and the SIM flex etc.
1.5 Error Beeps
If there are some error beeps, then make the difference between CPU–
and DRAM–related errors and proceed to the CPU/DRAM fault. If no
beeps are generated then proceed to 1.6
1.5.1.2 DRAM Fault
If DRAM related error beeps can be heard, then check the resistors R180
– R195. If they are OK, then the fault can be either in the CPU (D130) or
in the DRAM itself (D160). As the DRAM is easier to change, it is better to
try that first.
1.6 Reboot and PING from the PC Locals while in Testmode.
Next try to establish a connection from the service software to the PDA.
Activate the testmode pin of the PDA. Select a menu from the software
that pings the target, and then reboot the PDA.
Pinging the target sends bytes (55h) to the PDA via the serial RXD, and
waits for a response byte (AAh) from it via the TXD.
1.7 Respond to PING from the Target
If the target PDA respond to the host's request, the Power–On procedure
has succeeded and further tests can be carried out by proceeding to the
uppermost level of the fault finding tree.
If no acknowledge is received, then proceed to 1.7.1
1.7.1 RS–Buffer Activated?
If the service software cannot receive the acknowledgement, then the fault
can be in the CPU (D130), in the boot code that is located in the UCS
Flash device (D163), or in the connection between the CPU and the host
PC.
Original, 05/97
RAE/RAK–1N
Faultfinding/Disassembly
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