Pioneer DDJ-T1 Service Manual page 28

1
A
[4] USB connection
[4-1] The unit cannot be recognized by the PC when connected to the PC via USB connection.
Check the following, with a Windows/MAC PC connected via the USB port of the unit, using the supplied USB cable:
No. Cause/Symptom Point to be checked
UCOM/USBB
1 Failure in startup
Defective UCOM/USBB
2
USB_UCOM
B
[5] AUDIO OUT
[5-1] No signal is output from the MASTER connectors
No. Cause/Symptom Point to be checked
C
1 — MASTER1/2
2 — UCOM Assy
3 — UCOM Assy
D
Loose connection
4 UCOM Assy
/defective parts
Loose connection
5 UCOM Assy
/defective parts
E
Loose connection
6 UCOM Assy
/defective parts
Loose connection
7 JACB Assy
/defective parts
Loose connection
8 JACB Assy
/defective parts
F
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1
2
Item to be checked
Check the lighting statuses of the LEDs
during startup.
Assy
Check the communication waveforms of
the USB DP/DN lines.
Assy
Item to be checked
Identify the connector(s) that do(es) not
output signals.
Check the audio signal, using Pins 5 and 9
of the CN501 on the UCOM Assy.
Check that an audio signal is output from
DAC (IC506).
Check the digital input signals to DAC (IC506).
• DAC_RST
• MCLK
• BCLK
• LRCK
• MASTER_DATA
Check that the MUTE signal level is L
(muting canceled).
Check that the A_MUTE signal level is L
(muting canceled).
Identify the point where the audio signal is
interrupted on the line from CN4401 to the
jacks (JA4402/JA4404).
Identify the point where the audio signal is
interrupted on the line from CN4401 to the
jacks (JA4403).
2
3
How to distinguish a defective point and/or corrective action
If no LED lights, see [1] Failure in Startup.
If the unit is connected to a PC via the USB cable,
communication will be performed through the USB
DP/DN lines.
If communication cannot be performed, check the
USB cable, connectors, internal cables, resistors,
capacitors, and filters.
If nothing is wrong with them, check the items listed
in "Failure in the microcomputer system" and "USB
UCOM startup error."
How to distinguish a defective point and/or corrective action
Check if no signal is output from both MASTER 1 and 2 or
either of them.
• If neither MASTER 1 nor 2 connector outputs, go to [2].
• If only the MASTER 1 connector does not output, go to [7].
• If only the MASTER 2 connector does not output, go to [8].
If no audio signal is output, loose connection or
defective parts in the UCOM Assy may be suspected.
• If an audio signal is output, go to [7] or [8].
• If an audio signal is not output, go to [3].
• If an audio signal is output, go to [5].
• If an audio signal is not output, go to [4].
If any of the signals is not input, check the soldering
status of DAC (IC506).
If the level of DAC_RST is L, check the connections
of the MAIN_UCOM (IC701). If nothing is wrong with
the connec-tions, then the MAIN_UCOM (IC701)
itself may be defective.
If other signals are not input, check the connections
of the USB_UCOM (IC202). If nothing is wrong with
the connections, then the USB_UCOM (IC202) itself
may be defective.
If the MUTE signal level is L (muting canceled,)
check the connections between the DAC and CN501.
If nothing is wrong with the connections, soldering of
the OP amp (IC501) or the OP amp itself may be
defective.
If the MUTE signal level is H, go to [6].
If the A_MUTE signal level is L (muting canceled,)
check that the signal logics for Q583/Q505/Q506/
Q581/Q582 are the same as those described in the
schematic diagrams. If any of the signal logic is not
the same, repair the defective point.
If the A_MUTE signal level is not L (muting canceled),
the soldering status of the MAIN_UCOM (IC701) or
the MAIN_UCOM itself may be defective.
If the audio signal is interrupted at the periphery of
the OP amp (IC4403/IC4405), check the soldering
status of the OP amp. If it is properly soldered, then
the OP amp itself may be defective.
If the audio signal is interrupted at the periphery of
the OP amp (IC4404), check the soldering
status of the OP amp. If it is properly soldered, then
the OP amp itself may be defective.
DDJ-T1
3
4
Reference
[1] Failure in
Startup
Failure in the
microcomputer
system
USB_UCOM
startup error
10.17 WAVEFORMS
USB DP/DN (1),(2)
t, u
Reference
—
10.4 UCOM
ASSY (3/6)
10.4 UCOM
ASSY (3/6)
10.4 UCOM
ASSY (3/6)
10.17 WAVEFORMS
DAC reset cancel
DAC I2S (1),(2)
10.4 UCOM
ASSY (3/6)
10.17 WAVEFORMS
Output MUTE cancel
#
10.4 UCOM
ASSY (3/6)
10.17 WAVEFORMS
Output MUTE cancel
"
10.1 JACB ASSY
10.1 JACB ASSY
4