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Trouble Shooting Guide, Advanced
Go to Audio / Audio Fig. 21.2.
Start ATMS – PCM – AFMS.
An appropriate signal for ATMS is 1kHz, 100mVrms or 280mVp-p sinus.
Apply the signal with a zero ohm probe at J602: 2
Measure it with oscilloscope and standard probe at J602: 1.
If the signal does not exist at J600: 1, check if the signal exists at N800: 19 (75 mV rms. or 200
mV p-p sinus).
If the signal exists at N800: 19, the fault almost always is due to N800.
It can also be due to D600.
If the signal is correct at J602: 2, the fault is due to one of the components in the signal path,
C810, R802, C812 or a foil damage.
If the signal is too low or is missing at the system connector, the fault probably is due to bad
connections, broken cables, or wrong settings or connection for the signal generator.
The fault can also be due to bad contact surfaces at J602.
21.6 The AFMS part is out of order
When the AFMS part is out of order is it only the audio paths "Mic – AFMS", "ATMS – PCM –
AFMS" and "ATMS – CPU – AFMS" that is faulty.
The other two should be working.
The trouble shooting below assumes the system connector of the phone has been replaced, but
the fault remains, so then the fault is at the board.
Open the phone and check for liquid damages.
No further action should be taken for a liquid damaged telephone.
Make sure the system connector pads are not oxidised or burned.
Give the board power and start it in the test program.
Go to Audio / Audio Fig21.2.
Start ATMS – PCM – AFMS.
An appropriate signal for ATMS is 1kHz, 100mV rms. or 280mV p-p sinus.
Apply the signal with a zero ohm probe at J602: 2
Check if the signal exists at N800: 22 (125 mV rms. or 340mVp-p sinus).
If the signal is missing at N800: 22, the fault almost always is due to N800.
The fault can also be due to D600 or a short circuit in F601.
If the signal exists at N800: 22, check if it exists at the system connector, J602: 1 (125 mV rms.
or 340mVp-p sinus).
If the signal is too low or is missing at the system connector the fault is due to one of the
components in the signal path, R806, C813 or a foil damage.
If the signal is correct at the system connector, the fault probably is due to bad connections,
broken cables, or wrong settings or connection for the oscilloscope.
4/00021-3/FEA 209 544/18 B
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