23
DJM-850-K
5
6
7
8
5
6
7
8
A
B
C
D
E
F
2
Loose connection
/defective parts
MAI
N
Assy
IC1604 (CH1)
IC1
8
04 (CH2)
IC2004 (CH3)
IC2204 (CH4)
pin 4, 5, 24, 25
Representative
CH1_R-
/CH1_R+
[Checking the ADC block]
Check for an audio signal at the input
connector of ADC (IC1604/IC1
8
04/
IC2004/IC2204).
If no audio signal is input to ADC, a problem in
an analog circuit at a previous stage may be
suspected.
• If an audio signal is input, go to [3].
• If no audio signal is input, check for a part
where the signal is interrupted, by observing
the audio signal in the path from the input
connector to the ADC, then check the
soldering status and check for a defective
part in the corresponding part.
10.35
W
A
V
EFORMS
(CD input signal)
(PHO
N
O·MIC
input signal)
1-1
8
1-1
8
2-2
2-3
1-1
8
1-26
1-26
1-27
1-2
8
1-29
1-30
1-31
1-32
1-33
1-29
1-27 1-2
8
1-31 1-32 1-33
3
Loose connection
/defective parts
MAI
N
Assy
IC1604(CH1)
IC1
8
04(CH2)
IC2004(CH3)
IC2204(CH4)
pin 19
[Checking the ADC block]
Check for the RESET signal of ADC.
• If the RESET signal level is L, go to [6].
• If the RESET signal level is H, go to [4].
—————
4
Loose connection
/defective parts
MAI
N
Assy
IC1604 (CH1)
IC1
8
04 (CH2)
IC2004 (CH3)
IC2204 (CH4)
96k CLK: pin 17
Representative
6M CLK: pin 16
Representative
24M CLK: pin 1
8
Representative
[Checking the ADC block]
Check for the CLK signal of ADC.
• If no CLK signal is input, go to [7].
• If the CLK signal is input, go to [5].
10.35
W
A
V
EFORMS
5
Loose connection
/defective parts
MAI
N
Assy
IC1604(CH1)
IC1
8
04(CH2)
IC2004(CH3)
IC2204(CH4)
pin 15 Representative
[Checking the ADC block]
Check for the signal output from
ADC output terminal.
• If output signal cannot be confirmed, ADC
may be defective.
Check for the status of soldering and replace it.
• If output signal can be confirmed, DSP
(IC3201) must be improperly soldered or
defective.
10.35
W
A
V
EFORMS
10.35
W
A
V
EFORMS
6
Loose connection
/defective parts
MAI
N
Assy
IC2
8
04 pin 1, pin 3
[Checking the RESET signal path]
Check for the RESET signal.
• If the signal level at Pin 1 is H and that at
Pin 3 is L, IC2
8
04 must be soldered
impropely or defective.
• If the signal level at Pin 1 is L and there is no
abnormality in the path from the MAI
N
UCOM
(IC2
8
03) to IC2
8
04, soldering of the MAI
N
UCOM
(IC2
8
03) or the IC itself is defective.
—————
7
Loose connection
/defective parts
MAI
N
Assy
96k CLK: IC3006
pin 10, pin
8
6M CLK: IC3004
pin 10, pin
8
24M CLK: IC3005
pin 10, pin
8
[Checking the CLK signal path]
Check for the 96k CLK, 6M CLK and
24M CLK signals.
• If no signal is output from Pin 7 even though
Pin 4 is normal for CH1/CH3, or if no signal is
output from Pin 11 even though Pin 13 is
normal for CH2/CH4, soldering of IC3006/
IC3004/IC3005 or these ICs themselves are
defective.
• If Pin 4 is not normal for CH1/CH3 or if Pin 13
is not normal for CH2/CH4, and if there is no
abnormality in the path from the FPGA
(IC3007) to IC3006/IC3004/IC3005, soldering
of the FPGA (IC3007) or this IC itself is
defective.
1
Loose connection
/defective parts
I
N
PUT Assy
IC4002/IC4003 (CH1)
pin1
IC4004/IC4005 (CH2)
pin1
IC4202/IC4203 (CH3)
pin1
IC4204/IC4205 (CH4)
pin1
[Confirmation of input signal selection]
Check if the input signal selection at each
switching operational amplifier
(IC4002/IC4003/IC4004/IC4005/IC4202/
IC4203/IC4204/IC4205) is proper.
• If the selection is proper, go to [2].
• If the selection is not proper, soldering of parts
in the peripheral circuits of the switching
operational amplifiers or the control transistors
(Q4005/Q4006/Q4205/Q4206) is defective or
one or more of the parts is defective. Or part of
the circuit in the path from the MAI
N
UCOM
(IC2
8
03) to a control transistor may be
disrupted.
10.35
W
A
V
EFORMS
(CD)
(PHO
N
O)
2-1
2-1
2-1
[2] AUDIO INPUT
[2-1] No signal is input to the CD/LINE, PHONO connectors.
0
Prior
Confirmation
CD/LI
N
E, PHO
N
O,
LI
N
E, USB */*
selector switch
/ TRIM control
Confirm on the screen that the selector
is set properly.
—————
Operating
instructions
No.
Cause
Diagnostics Point
Item to be Checked
Corrective Action
Reference
1-1
8
1-19
1-20
1-21
1-22
1-23
1-24
1-25
