26
DJM-850-K
1
2
3
4
A
B
C
D
E
F
1
2
3
4
1-63
1-64
1-65
1-65
1-64
1-63
11
Loose connection
/defective parts
MAI
N
Assy
IC402 pin 1, pin 7
[Checking the MASTER2]
Check the waveform of IC402 output pin.
• If no signal is output, soldering of the IC402 or
the IC itself is defective.
• If signals are output, soldering of the output
capacitors (C425, C426), output resistor
(R427,
R42
8
) is defective or one or more of
those parts is defective.
Or the MUTE circuited is activated.
• If the MUTE circuited is activated, go to [17].
10.35
W
A
V
EFORMS
12
Loose connection
/defective parts
MAI
N
Assy
IC401 pin 1, pin 7
[Checking the REC]
Check the waveform of IC401 output pin.
• If signals are output from the DAC (Pins 37 and
39 of IC201) but not from IC401, soldering of
the IC401 block or some part in the block
is
defective.
• If no signal is output from the DAC (Pins 37,
and 39 of IC201), go to [3].
• If signals are output from Pins 1 and 7 of
IC401, soldering of the output capacitors
(C423, C424), output resistor (R422, R425,
R419 and R426) is defective or one or more of
those parts is defective.
Or the MUTE circuited is activated.
• If the MUTE circuited is activated, go to [17].
10.35
W
A
V
EFORMS
13
Loose connection
/defective parts
MAI
N
Assy
IC502 pin 1, pin 7
[Checking the BOOTH Shaping
N
oise Filter]
Check the waveform of IC502 output pin.
• If signals are output from Pins 1 and 7 of
IC502, go to [14].
• If signals are output from the DAC (Pins 41
and 43 of IC201) but not from Pins 1 and 7 of
IC502, soldering of IC502, or IC502 block is
defective or one or more of those parts is
defective.
• If no signal is output from the DAC (Pins 41
and 43 of IC201), go to [3].
10.35
W
A
V
EFORMS
7
Loose connection
/defective parts
MAI
N
Assy
IC2
8
04
pin4, pin 6
[Checking the RESET signal path]
Check for the RESET signal.
• If the signal level at Pin 4 is H and that at
Pin 6 is L, IC2
8
04 must be soldered
impropely or defective.
• If the signal level at Pin 4 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.
—————
8
Loose connection
/defective parts
MAI
N
Assy
96k CLK: IC3006
pin 1, pin 3
6M CLK: IC3004
pin 1, pin 3
24M CLK: IC3005
pin 1, pin 3
[Checking the CLK signal path]
Check for the 96k CLK, 6M CLK and
24M CLK signals.
• If no signal is output from Pin 3 even though
Pin 1 is normal, soldering of the IC3006/
IC3004/IC3005 or these ICs themselves are
defective.
• If Pin 1 is not normal 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.
10.35
W
A
V
EFORMS
9
Loose connection
/defective parts
MAI
N
Assy
IC301 pin 1, pin 7
IC302 pin 1, pin 7
[Checking the MASTER Shaping
N
oise Filter]
Check for the DAC differential audio signal
output.
Check the waveforms of the signals
output pins of IC301/IC302.
• If a signal is output from the Pin 1/Pin 7 of
IC301/IC302, go to [10] and [11].
• If signals are output from the DAC (Pins 29,
31, 33 and 35 of IC201) but not from Pins 1
and 7 of IC301/IC302, soldering of the
IC301/IC302 block or some part in the block
is
defective.
• If no signal is output from the DAC (Pins 37,
39, 41and 43 of IC123), go to [3].
10.35
W
A
V
EFORMS
1-55
1-56
1-56 1-57 1-5
8
1-57
1-59
1-59 1-60
1-60
1-61
1-62
10
Loose connection
/defective parts
MAI
N
Assy
IC303 pin 1, pin 7
IC304 pin 1, pin 7
[Checking the Balanced Output AMP]
Check the waveforms of the signals from
the output pins of IC303/304.
• If no signal is output, soldering of the IC303/
IC304 is defective or the ICs themselves are
defective.
• If signals are output, soldering of the output
capacitors (C355, C356, C357, C35
8
) or the
ICPs (P302, P301) is defective or the
capacitors or ICPs themselves are defective.
Or the MUTE circuited is activated.
• If the MUTE circuited is activated, go to [15].
10.35
W
A
V
EFORMS
1-61 1-62
1-5
8
1-66
1-66 1-67
1-67
14
Loose connection
/defective parts
MAI
N
Assy
IC503 pin 1, pin 7
IC504 pin 1, pin 7
[Checking the BOOTH Balanced Output AMP]
Check the waveform of IC503/IC504
output pin.
• If no signal is output, soldering of the IC503/
IC504 or the IC itself is defective.
Or the MUTE circuited is activated.
• If signals are output, soldering of the output
capacitors (C553, C554, C555 and C556),
output resistor (R542, R545, R54
8
and R551)
is defective or one or more of those parts is
defective. Or the MUTE circuited is activated.
• If the MUTE circuited is activated, go to [17].
10.35
W
A
V
EFORMS
No.
Cause
Diagnostics Point
Item to be Checked
Corrective Action
Reference
