Audio Troubleshooting; Audio Troubleshooting Test Instructions; Test Procedure - Nokia RM-632 Service Manual

Audio troubleshooting

Audio troubleshooting test instructions

Differential external earpiece and internal earpiece outputs can be measured either with a single-ended or
a differential probe.
When measuring with a single-ended probe each output is measured against the ground.
Internal handsfree output is measured using a current probe, if a special low-pass filter designed for
measuring a digital amplifier is not available. Note also that when using a current probe, the input signal
frequency must be set to 2kHz.
The input signal for each loop test can be either single-ended or differential.
Required equipment
The following equipment is needed for the tests:
• Oscilloscope
• Function generator (sine waveform)
• Phoenix service software
• Battery voltage 3.7V

Test procedure

Audio can be tested using the Phoenix audio routings option. These different audio loop paths can be
activated:
• Mic2P to Internal earpiece
• Mic2P microphone to Internal handsfree speaker
Each audio loop sets routing from the specified input to the specified output enabling a quick in-out test.
Loop path gains are fixed and they cannot be changed using Phoenix. Correct pins and signals for each test
are presented in a table in the following section.
Phoenix audio loop tests and test results
The results presented in this table apply when no accessory is connected and battery voltage is set to 3.7V.
Earpiece, internal microphone and speaker are in place during measurement. Applying a headset accessory
during measurement causes a significant drop in measured quantities.
The gain values presented in the table apply for a differential output vs. single-ended/differential input.
Loop test
terminal
External Mic to E2005
Internal
Earpiece
External Mic to E2005
Internal
handsfree
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Input Output
terminal
EarP and
EarN
IHFSpLP
and
IHFSpLN
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BB Troubleshooting and Manual Tuning Guide
Path Input
gain [dB] voltage
(fixed) [mVp-p]
~9 100
~16 100
RM-632; RM-634; RM-699
Differential Output
output DC level
voltage [V]
[mVp-p]
288 NA
600 NA
Output
current
[mA]
NA
NA
Issue 3