Audio Troubleshooting; Audio Troubleshooting Test Instructions - Nokia 6720 Service Manual

Audio troubleshooting

Audio troubleshooting test instructions

External earpiece, internal earpiece and internal handsfree 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.
The input signal for each loop test is single-ended.
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. Three different audio loop paths are used in
the tests:
• AV mic to AV ear
• AV mic to HP ear
• Ext microphone in Int handsfree out
Note: The internal uplink microphones can be tested using the Phoenix self test "ST-DIGIMIC-TEST".
If the test result is PASS, the uplink microphones are electrically OK. For more thorough testing, see
section Internal microphone troubleshooting (page
Each audio loop sets routing from the specified input to the specified output enables 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 speakers 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
AV mic to AV ear HS_MIC
and GND
Page 3 –50
Input Output
terminal
HS_EAR_R and
GND
HS_EAR_L and
GND
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BB Troubleshooting and Manual Tuning Guide
3–55).
Path gain Input voltage,
[dB] (fixed) 1 kHz sine
[mVp-p]
+21.3 100
RM-424; RM-564
Single-ended Output
output DC level
voltage [mVp- [V]
p]
584 0
Issue 1