Nokia 5110 Service Manual

PAMS

Technical Documentation

NSE–1

Disassembly & Troubleshooting Instructions

Page 11

Original  03/98

This fault means that software is able to run and  thus the watchog of
CCONT (N100) can be served.
Selftest functions are run when power is switched on and  software is
started to excute from flash.
If any of selftests is failed, contact service information will be shown on
display.

If the phone doesn’t register to the network or the phone doesn’t make a
call, the reason could be either the baseband or the RF part.
The phone can be set to wanted mode by WinTesla service software and
determinate  if the fault is in RF or in baseband part (RF interface mea-
surements).

The control lines for RF part are supplied both the System Asic
(MAD2;D200) and the RFI (Cobba; N250). MAD2 handles digital control
lines ( like synthe, TxP etc.) and Cobba handles analog control lines (like
AFC, TxC etc.).

The DSP software is constructed so that operation states of DSP (MAD2)
can be seen in external flag (DSPXF) output pin (D200 pin 91).

After power up, DSP signals all completed functions by changing the state
of the XF pin (see figures 39 and 40).

MAD2 pin 91 (DSPXF)

1

2

3

1. DSP initialization done

2.Synchronization to network 
   done

3. Registrarition to network 
    done.

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