17
DDJ-RB
5
6
7
8
5
6
7
8
A
B
C
D
E
F
1
Failure in LED
lighting
DCK1 Assy
DCK2 Assy
MXR Assy
In each mode where the abnormal LED
should be lit, check the GRID signals
(GRID_0 to GRID_3) relating to the
abnormal LED between the UCOM and
the transistor for driving the corresponding
LED.
If the waveform is abnormal, connection of the
GRID signal line may be loose or the resistor,
capacitor, or transistor may be defective.
If nothing is wrong with these parts, the UCOM
(IC406) may be defective.
10.13 WAVEFORMS
STUV
4
Failure in button
operation
DCK1 Assy
DCK2 Assy
MXR Assy
When pressing the abnormal button, check
the GRID signal (GRID_0 to GRID_3)
corresponding to the abnormal key
between the UCOM and the switch
for the corresponding key (S****).
If the waveform is abnormal, connection of the
KEY-detection signal line may be loose or the
resistor, capacitor, or transistor may be defective.
If nothing is wrong with these parts, the
UCOM (IC406) may be defective.
10.13 WAVEFORMS
STUV
7
Failure in operation
of the
performance pad,
volume,
tempo slider, fader,
rotary selector, or
Jog dial (touching
and rotating)
DCK1 Assy
DCK2 Assy
MXR Assy
MAIN Assy
Check the waveform of each input signal
to the UCOM (IC406) when you operate
the abnormal operating element.
If the waveform is abnormal, connection of the
corresponding signal line may be loose or the
resistor, capacitor, or transistor may be defective.
If nothing is wrong with these parts, the
UCOM (IC406) may be defective.
10.13 WAVEFORMS
PYZ!"#$
%&'*+
5
DCK1 Assy
DCK2 Assy
MXR Assy
MAIN Assy
When pressing the abnormal button, check
the KEY detection signal between the
abnormal key and the transistor for key
detection.
If the waveform is abnormal, connection of the
KEY-detection signal line may be loose or the
switch, transistor, or diode may be defective.
10.13 WAVEFORMS
SWX
6
DCK1 Assy
DCK2 Assy
MXR Assy
MAIN Assy
When pressing the abnormal button, check
the KEY-detection signal (KEY_0 to
KEY_11) corresponding to the abnormal
key between the transistor for key detection
and the UCOM.
If the waveform is abnormal, connection of the
KEY-detection signal line may be loose or the
resistor, capacitor, or transistor may be defective.
If nothing is wrong with these parts, the
UCOM (IC406) may be defective.
10.13 WAVEFORMS
SWX
2
DCK1 Assy
DCK2 Assy
MXR Assy
In each mode where the abnormal LED
should be lit, check the LED-driving signal
between the transistor for driving the
corresponding LED and the abnormal LED.
If the waveform is abnormal, connection of the
LED-driving signal line may be loose or the
resistor, transistor, or diode may be defective.
10.13 WAVEFORMS
S,./
3
DCK1 Assy
DCK2 Assy
MXR Assyy
In each mode where the abnormal LED
should be lit, check the LED-control signal
(LED_0 to LED_13) corresponding to the
abnormal LED between the transistor for
driving the corresponding LED and the
UCOM.
If the waveform is abnormal, connection of the
LED-control signal line may be loose or the
resistor, capacitor, or transistor may be defective.
If nothing is wrong with these parts, the
UCOM (IC406) may be defective.
10.13 WAVEFORMS
S,./
No.
Cause
Diagnostics Point
Item to be Checked
Corrective Action
Reference
[7] Basic Operation Check of the MAIN UCOM
Note:
First, check if the voltage at each section is OK.
Operation checking of all operating elements and LEDs can be performed in Service mode. With regard to operation
checking of LED lighting, besides lighting of each LED, check that all LEDs can be simultaneously lit or unlit.
