20
DJM-850-K
1
2
3
4
A
B
C
D
E
F
1
2
3
4
5.2 TROUBLESHOOTING
[0] Prior Confirmation
[0-1] Checking Internal Cables
No.
Cause
Diagnostics Point
Item to be Checked
Corrective Action
1
Disconnection,
breakage, or
loose connection
of internal cables
Relevant part
Check that all the cables are securely
connected.
Check that there is no breakage in the
cables.
Securely connect the cables. If a cable is
broken, replace it.
4.1 O
V
ERALL
CO
NN
ECTIO
N
DIAGRAM
Reference
No.
Cause
Diagnostics Point
Item to be Checked
Corrective Action
Reference
[1] Failure in Startup
[1-1] The unit dose not turn on, and the LED of the SETUP LED does not flash.
1
Circuit failure
Excessive power
supply voltage
injection
PRIMARY Assy
FU1
Check the primary side fuse.
• If blowing of the fuse is visible, go to [2].
• If blowing of the fuse is not visible, go to [3].
—————
Contents
[0] Prior Confirmation
[0-1] Checking Internal Cables
[1] Failure in Startup
[1-1] The unit dose not turn on, and the LED of the
SETUP LED does not flash.
[1-2] The unit dose not turn on, and the LED of the
SETUP LED flashes four times.
[1-3] The unit dose not turn on, and the LED of the
SETUP LED flashes two times.
[1-4] The unit dose not turn on, and the LED of the
SETUP LED flashes five times.
[1-5] The unit dose not turn on, and the LED of the
SETUP LED flashes once.
[1-6] The unit dose not turn on, and the LED of the
SETUP LED flashes six times.
[1-7] The unit dose not turn on, and the LED of the
SETUP LED flashes endlessly.
[2] AUDIO I
N
PUT
[2-1]
N
o signal is input to the CD/LI
N
E, PHO
N
O
connectors.
[2-2]
N
o signal is input to the MIC1/MIC2
connectors.
[2-3]
N
o signal is input to the RETUR
N
connector.
[3] AUDIO OUTPUT
[3-1]
N
o signal is output from the MASTER1/
MASTER2/REC/BOOTH connectors.
[3-2]
N
o signal is output from the SE
N
D connector.
[3-3]
N
o signal is output from the PHO
N
ES
connector.
[3-4]
N
o signal is output from the DIGITAL
MASTER OUT connector.
[4]
USB
[4-1] Co connection to the PC,
N
o signal is input to
and output from the USB connector.
[4-2]
N
o timecode signal input to the mixer.
[5]
FL
[5-1] The FL does not light.
[6]
CO
N
TROL
[6-1] The FADER START function does not work
*Point to be checked – Assys are classified with prefix.
[1-**] MAI
N
Assy
[2-**] I
N
PUT Assy
[3-**] P
N
LA Assy
[4-**] SEC/HP Assy
[5-**] PRIMARY Assy
The fuse may be blowout or
V
+11E_U
N
REG,
V
+3R3E power failure or MAI
N
UCOM (IC2
8
03), FLASH (IC2
8
02) startup error may be suspected.
5-1
2
Power failure
Each power supply
Check if any power supply is
short-circuited to ground.
• If any power supply is short-circuited, repair it.
• If no power supply is short-circuited, replace
the
fuse.
4.4 PO
W
ER
BLOCK DIAGRAM
1-2
4
Power failure,
defective parts
MAI
N
Assy
IC1401 pin 4
Check for the
V
+3R3E power.
• If the
V
+3R3E power can be confirmed,
go to [5].
• If the
V
+3R3E power cannot be confirmed,
the
3.3
V
REGULATOR (IC1401) block may be
defective. Check for the status of soldering and
replace
it.
4.4 PO
W
ER
BLOCK DIAGRAM
5.3 I
N
FORMATIO
N
O
N
PO
W
ER
DIAG
N
OSTICS
1-3
5
RESET signal
error
MAI
N
Assy
IC2
8
03 pin 90
Check for the CPU_RESET signal.
• If the IC103_1 pin is high level, go to [6].
• If the IC103_1 pin is not high level, the RESET
IC
(IC2
8
01) block may be defective. Check for
the status of soldering and replace it.
—————
1-1
3
Power failure
MAI
N
Assy
C
N
1201 pin 3
Check for the
V
+11E_U
N
REG power.
• If the
V
+11E_U
N
REG power can be confirmed,
go to [4].
• If the
V
+11E_U
N
REG power cannot be
confirmed, go to [7].
4.4 PO
W
ER
BLOCK DIAGRAM
5.3 I
N
FORMATIO
N
O
N
PO
W
ER
DIAG
N
OSTICS