Yamaha MU100 Service Manual page 21

When a sine wave signal of -11.5 dBm, 1 kHz is applied to
A/D INPUT (L), and A/D INPUT is set at maximum, and
A/D INPUT (R) is connected to the ground:
OUTPUT (L): +5 dBm +/-2 dB (10 ohm load), distortion
0.5 % or less
OUTPUT (R): less than -60 dBm
When a sine wave signal of -11.5 dBm, 1 kHz is applied to
A/D INPUT (R), and A/D INPUT is set at maximum, and
A/D INPUT (L) is connected to the ground:
OUTPUT (L): less than -60 dBm
OUTPUT (R): +5.0 dBm +/-2 dB (10 k ohm load),
distortion 0.5 % or less
When a sine wave signal of -11.5 dBm, 1 kHz is applied to
A/D INPUT (L), and A/D INPUT is set at minimum, and
A/D INPUT (R) is connected to the ground:
OUTPUT (L): less than -65 dBm
When a sine wave signal of -11.5 dBm, 1 kHz is applied to
A/D INPUT (R), and A/D INPUT is set at minimum, and
A/D INPUT (L) is connected to the ground:
OUTPUT(R): less than -65 dBm
Check that the level meters on the LCD will light up, when
the sine wave of -6.0 dBm +/-2 dB, 1 kHz is applied to the
A/D INPUT (R).
TEST END
Press the [ENTER] button. The MU100 will then
automatically proceed to the next test.
If the [EXIT] button is pressed, the MU100 will wait for
the entry of the test number.
17. MEG&DRAM
17 MEG&DRAM
Check that the correct signal is output from OUTPUT (L) jack.
Insert the appropriate phone plug into the OUTPUT (L)
jack and check the output.
If necessary, verify the frequency, output waveform, output
level, and THD of the OUTPUT (L,R) and the PHONES
outputs using a frequency counter, oscilloscope, AC
voltmeter(with 12.47 kHz filter) and distortion meter. The
VOLUME control must be set at maximum for this check.
ITEMS TO BE CHECKED
OUTPUT(L): 1 kHz +/-3.0 Hz, sine wave, +2 dBm +/-2 dB
(10 k ohm load), distortion 0.25 % or less
TEST END
Press the [ENTER] button. The MU100 will then
automatically proceed to the next test.
If the [EXIT] button is pressed, the MU100 will wait
for the entry of the test number.
18. 64 SOUND OUTPUT TEST
18 64ch OUT
Check that the correct sine wave signals from channel 1 to
channel 32 are output from the OUTPUT (L) and channel
33 through channel 64 are output from the OUTPUT (R).
If necessary, verify the output waveform using an
oscilloscope (L channel: 1 kHz, R channel: 2 kHz).
The VOLUME control must be set at maximum for this check.
While sounding, the LCD will display the following message.
18 64ch OUT
Lch=xx
(Where xx: currently sounded channel)
TEST END
Press the [ENTER] button. The MU100 will then
automatically proceed to the next test.
If the [EXIT] button is pressed, the MU100 will wait for
the entry of the test number.
19. FACTORY SETTINGS
19 FACTORY SET
This test is used to initialize the data to the factory settings.
If the [ENTER] button is pressed, the factory preset data
will be restored. The MU100 will then exit the test program
mode and enter to play mode.
If the [EXIT] button is pressed, they will not be restored.
20. EXIT
20 EXIT
When the [ENTER] button is pressed, the MU100 will exit
the test program mode and enter to the play mode.
To remain in the test program, press the [EXIT] button. The
MU100 will then wait for the entry of the test number.
Check that the noise levels are as follows, after the MU100
has quit the test program.
OUTPUT (L): -88 dBm as follows
OUTPUT (R): -88 dBm as follows
PHONES (L): -88 dBm as follows
PHONES (R): -88 dBm as follows
21. PB1 NAME TEST
21 PB1 NAME
After transmitting the request of the circuit board name and
version, the MU100 receives the data through the MU-PB
wires and the CN1 connector, and displays it on the LCD.
Check the circuit board name and version on the LCD.
MU100
Rch=xx
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