Roland Boss ME-50 Service Notes page 17

Feb.2003
fig.test-27_50
• Press the [ ] switch to proceed to the next step.
10. INPUT A/D Check, AUX IN Check,
Noise Check
fig.test-28_70
(1) INPUT A/D Check
Input a rectangular wave to the INPUT jack only, then check the waveform
from OUTPUT.
• INPUT Signal: 400-Hz, 50-mVp-p square wave
• Oscilloscope Settings: Ch1: 0.2 V/div; Ch2: 0.2 V/div; TIME: 0.5 ms/div
• Confirm that the value for the waveform amplitude is between 320 and
460 (mVp-p).
fig.test-29_50
(2) AUX IN Check
Input a rectangular wave to the AUX IN jack only, then check the waveform
from OUTPUT.
• INPUT Signal: 400-Hz, 200-mVp-p square wave
• Oscilloscope Settings: Ch1: 0.2 V/div; Ch2: 0.2 V/div; TIME: 0.5 ms/div
• Confirm that the value for the waveform amplitude is between 400 and
560 (mVp-p) GUITAR/AMP Jack.
18
fig.test-30_50
• Confirm that the LINE/PHONES waveform amplitude is between 290
and 410 (mVp-p).
(3) INPUT-to-OUTPUT Noise Check
• Disconnect cable connected to INPUT and AUX IN.
• Listen to the noise and confirm the following.
1.
Noise level is -83.0 dBm IHF-A (JIS-A) or lower (both L and R).
2.
No abnormal sounds are mixed with the output sound.
3.
No abnormal sounds occur when the unit is subjected to shock.
• Press the [ ] switch to proceed to the next step.
11. EXP Pedal Adjustment
fig.test-31_70
fig.test-32_70
• Raise the unit's expression pedal completely, release the pedal, and press
the [WRITE] switch.