Pioneer DDJ-T1 Service Manual page 30

1
A
[7] Basic Operation Check of the MAIN_UCOM
Note: First, check if the voltage at each section is OK.
No. Cause/Symptom Point to be checked
1
UCOM Assy
GRID Operation
Check
(No operation
with keys, VRs,
UCOM Assy
sliders, or LEDs)
Assy
2
corresponding
B to each key
3
UCOM Assy
KEY Buffer
operation (key
input disabled)
UCOM Assy
Assy
4
corresponding
to each key
C
D
E
F
30
1
2
Item to be checked
Check the power to and the input/output
waveforms of the GRID IC (IC702)
Check the output waveform of the GRID IC
(IC702), with the FFC cable of the UCOM
Assy disconnected.
Check the power supply to the KEY Buffer
ICs (IC1101 and 1102) and the input/output
waveforms when a key is pressed.
Check the connection of the FFC cable.
Check also the key input circuit of the PCB
Assy connected.
DDJ-T1
2
3
How to distinguish a defective point and/or corrective action
If the waveform is not proper, check the GRID line
and the parts, such as resistors and capacitors.
If the output waveform is not proper, check item [2].
If nothing is wrong with the parts, the GRID IC
(IC702) or the MAIN_UCOM (IC701) may be
defective.
If the waveform returns to normal, the PCB Assy that
is connected with the UCOM Assy via the FFC cable
may be defective.
If the waveform does not return to normal, the GRID
IC (IC702) may be defective.
If the input waveform appears but the output
waveform does not when a corresponding key is
pressed, the KEY Buffer ICs (IC1101 and 1102) may
be defective.
If the input waveform does not appear when a
corresponding key is pressed, check item [4].
If the key input circuit of the board connected is
normal, the KEY Buffer ICs (IC1101 and 1102) may
be defective.
3
4
Reference
10.17 WAVEFORMS
GRID control 1,
GRID control 2
10.17 WAVEFORMS
GRID control 1,
GRID control 2
No operation
button is
effective.
10.17 WAVEFORMS
KEY operation 1,2
10.7 UCOM
ASSY (6/6)
4