Yamaha A4000, Service Manual

Page: 27 / 61

A5000/A4000
27
25 DIGITAL IN
Insert the appropriate phone plugs into the STEREO OUT-L termi-
nal. Input the signal to the DIGITAL IN terminal. Check the output
wave form and the output level of each output by using an oscillo-
scope, an AC voltmeter (with JIS-C filter) and a distortion factor
meter. Check that the following signal is output. And while executing
the test, check the error isn’t displayed. If the test is performed again
, push the STOP and execute the test again. The REC GAIN and the
MASTER VOLUME control must be set at maximum for these
checks.
Input sine wave signal : 0 dBm, 1 kHz +/- 5 Hz, less than 0.005%
distortion
impedance 600 ohm
STEREO OUT-L: 1 kHz +/- 5 Hz, sine wave, less than 0.2% distortion
+17 +/- 4 dBm (10 k ohm load)
RESULT OF THE TEST
OK :
NG :
END OF THE TEST
After pressing the [ENC5] STOP, the test will be finished.
26 OPTICAL IN
Insert the appropriate phone plugs into the STEREO OUT-L termi-
nal. Input the signal to the OPTICAL IN terminal. Check the output
wave form and the output level of each output by using an oscillo-
scope, an AC voltmeter (with JIS-C filter) and a distortion factor
meter. Check that the following signal is output. And while executing
the test, check the error isn’t displayed. If the test is performed again
, push the STOP and execute the test again. The REC GAIN and the
MASTER VOLUME control must be set at maximum for these
checks.
Input sine wave signal : 0 dBm, 1 kHz +/- 5 Hz, less than 0.005%
distortion
impedance 600 ohm
STEREO OUT-L: 1 kHz +/- 5 Hz, sine wave, less than 0.2% distortion
+17 +/- 4 dBm (10 k ohm load)
RESULT OF THE TEST
OK:
NG :
END OF THE TEST
After pressing the [ENC5] STOP, the test will be finished.
27 mLAN I/F (26pin)
Execute the test. Command to execute to the mLAN circuit board.and
automatically perform the following items in serial order. Insert the
appropriate phone plugs into the STEREO OUT-L, R terminal. Check
by listening that the notes of each output are generated by using a
speaker.
1) Test of connecting board Find the mLAN board is in or out.
2) Board test entry
Command to execute the test to the
mLAN board.
3) MEL output test Execute the output (4 system) test from
the body to the mLAN board. Con-
cretely, output the sine wave in order
for the mLAN board from the body and
check the signal of the mLAN board is
the appointed level.
4) MEL input test Execute the input (1 system) test from
the mLAN board to the body.
Concretely output the sine wave for
the mLAN and the mLAN board out-
puts the signal to the MEL insert of the
body.
And the body outputs the signal to the
STEREO OUT changing the D/A.
5) Inside clock test Execute the test by using the quartz
crystal oscillator built-in the sound
clock.
6) mLAN clock test Change the sound clock from the mLAN
to the clock and execute the sound test.
7) Board reset Initialize the mLAN board.
According to the 4), 5), 6), check by listening the sine wave is gener-
ated. According to the 1), 2), 3), 7), the mLAN circuit board and the
body are automatically judged and check the test result on the LCD.
4) When executing the MEL insert test, the display is as below.
5) When executing the inside clock test, the display is as below.
2 5 : D I G I TA L I N
AUTO MANUAL
2 5 : D I G I TA L I N
ERROR STOP
2 6 : O P T I C A L I N
AUTO MANUAL
2 6 : O P T I C A L I N
ERROR STOP
2 7 : m L A N I / F ( 2 6 p i n )
AUTO MANUAL
2 7 : m L A N I / F ( 2 6 p i n )
E X T E R N A L M E L C H E C K CONT STOP
2 7 : m L A N I / F ( 2 6 p i n )
U S I N G I N T E R N A L C L O C K CONT STOP
2 5 : D I G I TA L I N OK
OK AUTO MANUAL
2 6 : O P T I C A L I N OK
OK AUTO MANUAL