Pioneer DDJ-SR Service Manual page 24

1
(2) Volume value fluctuation check mode
A
[Overview]
Will be tested fluctuation of voltage (A/D conversion value) which is made each Fader and Rotary volume by Level indicator.
[Use of this mode during repair]
• For failure judgment of the rotary VRs
As a guide, amplitude values higher than +4 or lower than -4 may be judged as failure.
The VRs can be set to any position during measurement. Possible symptoms are shown below.
• The volume changes arbitrarily.
• Interrupted sound leakage occurs even if the volume is decreased to the minimum at the Master or Booth Monitor.
• The MIDI signal is output even if the corresponding VR is not operated.
B
• For operation check of a rotary VR after replacement
[Knobs under test operation]
Knobs under test operation are filled blue as below.
C
1 1
D
7
[Test detail]
1 Choose the test subject by turn left and right Rotary selector.
The LED is lit with the following turns every 1 click.
E
Turn right: 1 → 2 → 3 → 4 → . . . . . → 25 → 26 → 1 → . . .
Turn left: 26 → 25 → 24 → . . . . . → 2 → 1 → 26 → . . .
Note: Regarding No.15, both LED are lit.
2 You can see what knob/fader is selected by Lighting LED on each button as shown in the above figure.
For example ,LED to test Channel fader is "Headphone CUE/TAP" button's LED.
3 When targeted knob is decided, push the Rotary selector and start observation of A/D conversion value.
Get the A / D conversion value immediately after the start. It will be reference value.
*A/D conversion value to be monitored is Raw data.
4 Start monitoring and later to monitor the A/D conversion value, do the following actions depending on its value with
F
Master level indicator.
24
1
2
Test subjects to move by turning right / left-turn Rotary selector.
A/D conversion value observation start/reset by push the Rotary selector.
6
2 3 4
5
11 11
8 9 10 10
15 15
2
3
16 16
22 22
21 21
12 12
13 13
17 17
14 14
DDJ-SR
3
4
23 23 24 24 25 25
26 26
18 18 19 19 20 20
4