Roland JD-XA Service Notes page 33

Jul. 2015
3. Pulse Width Check
This verifies the Duty ratio of pulse wave of oscillator.
+————————————————+
|A1-OSC1: PW 10%|
|Press [ENTER]
+————————————————+
1.
Verify that the pulse width shown in the figure is shorter than 0.3 ms.
fig.test-a-3-1.eps
Negative Width
2.
Press Enter.
A screen like the one shown below is displayed.
+————————————————+
|A1-OSC1: PW 50%|
|Press [ENTER]
+————————————————+
3.
Verify that the pulse width shown in the figure is in the range of 0.9 to
1.4 ms.
fig.test-a-3-2.eps
Negative Width
4.
Press Enter.
Execution advances to the check of the next wave form.
5.
For A1-OSC2, A2-OSC1, A2-OSC2, A3-OSC1, A3-OSC2, A4-OSC1 and
A4-OSC2, verify in the same way as steps 1 through 4.
6.
Press to advance to the next test item.
|
|
4. VCF1 Check
This verifies the circuit of VCF1 (4-pole OTA Filter).
+————————————————+
|A1-VCF1: CUT Min|
|Press [ENTER]
+————————————————+
1.
Verify that the frequency of the signal shown in the figure is lower than
40 Hz.
fig.test-a-4-1.eps
2.
Press Enter.
A screen like the one shown below is displayed.
+————————————————+
|A1-VCF1: CUT Max|
|Press [ENTER]
+————————————————+
3.
Verify that the frequency of the signal shown in the figure is higher than
8 kHz.
fig.test-a-4-2.eps
4.
Press Enter.
A screen like the one shown below is displayed.
+————————————————+
|A1-VCF1: RES Min|
|Press [ENTER]
+————————————————+
5.
Verify that no signal is output, and then press Enter.
Execution advances to the check of the next wave form.
6. For A2-VCF1, A3-VCF1 and A4-VCF1, verify in the same way as steps 1
through 5.
7.
Press to advance to the next test item.
JD-XA
|
|
|
33