
SG-2000 MANUAL
188
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©1995, SGC, Inc.
TEL: (206) 746-6310 FAX: (206) 746-6384
23.3.7
Speaker Level Check
Change the distortion analyzer to 0.3 VRMS range.
Adjust the audio generator for 100 mVRMS reading on the distortion analyzer.
Increase the audio volume to the maximum level.
Measure and record the voltage across the SPKR resistor with the oscilloscope.
Ensure the speaker is enabled, signal should be a clean sine wave:
SPKR
= 8 Vpp to 10Vpp
If test failed, check for the following levels:
IC11 Pin 9 .05
Vpp
IC11 Pin 10 .05
Vpp
IC11 Pin 8 540
mVpp
IC16 Pin 8 540
mVpp
IC16 Pin 11 60
mVpp
IC20 Pin 2 5
mVpp
IC20 Pin 1 .5
Vpp
IC18 Pin 1 .3
mVpp
IC18 Pin 4 8-10
Vpp
23.3.8
Phone Level Check
Turn speaker off by pressing SPKR 4 key, increase volume to the maximum
level then measure and record the voltage across the FONE resistor with the
same 100 mV audio signal.
FONE
= .6 to .8 Vpp
If test fails, check for the following levels:
IC19 Pin 9 .5
Vpp
R81 & C44 60
mVpp
IC17 Pin 3 40
mVpp
Output
.6 to .8
Vpp