Denon DN-S3700 Service Manual page 28

FLOW CHART NO.7 (8U-310011:MAIN UNIT)
+12V is not outputted.
Is 3.3V voltage supplied to 7pins(PVCC) of IC403?
Yes
Check IC403 and the periphery circuit, and replace
it if defective.
FLOW CHART NO.8 (8U-110043:PANEL UNIT)
The VFD does not light up.
Is 3.3V voltage supplied to 44pins(VDD) of FL901?
Yes
Is 40V voltage supplied to 41pins(HV2) of FL901?
Yes
Is 30V voltage supplied to 40pins(HV1) of FL901?
Yes
Are the filament voltage supplied between 1pin
and 49pin of the fluorescent display tube (FL901)?
Yes
Is voltage supplied to 34pins(RESET) of FL901?
Yes
Replace the fluorescent display tube(FL901).
FLOW CHART NO.9 (8U-110043:PANEL UNIT)
The key operation is not functioning.
Are the contact point and the installation state of the
tact switche normal?
Yes
Does LED light correctly ?
Yes
When pressing each switches, do the voltage of
each pin of IC702 increase?
Yes
Replace IC702(IC802).
FLOW CHART NO.10 (8U-110042:POWER UNIT)
Both functions of picture and sound do not operate normally.
The USB memory in which test signal (MP3,WAV)
of 1kHz/0dB is written is prepared.
With USB memory playback mode, with the test signal
of 1kHz/0dB it repeats between B from A and puts in
playback state.
Are the audio signals outputted to 11,12pin(Rch) and
17,18pin(Lch) of IC802?
Are the audio signals outputted to 7pin(Rch) and
1pin(Lch) of IC804?
Is the TR807 collector L (-9V) when muting
is canceled?
Check periphery circuit from 7pin and 1pin to
JK801 of IC804, and
replace
No
No
No
No
No
No
No
No
No
No
Yes
No
Yes
No
Yes
it if defective.
DN-S3700
Check whether parts C426 and C427 are linked,
short-circuited or open and whether FB402 is open,
and replace any faulty parts.
Check the +3.3V line and service it if defective.
Check the HV(+40V) line and service it if defective.
Check ZD901 and the periphery circuit, and service
it if defective.
Check the F1/F2 line and service it if defective.
Check the RESET line and service it if defective.
Re-install the switches correctly or replace
the poor switch.
Check the TR701~708and their periphery, and service
it if detective.
Check the switches and their periphery, and service
it if detective.
Check the input signal from CY112 to IC802 and their
periphery, and service it if detective.When the
input signal is correct, IC802 or IC803 is replaced.
(Note:For the IC802 OUT signal,
the right and left are inversely output internally.)
Check periphery circuit from 14pin and 15pin to
IC804 of IC802, and service it if defective.
When the periphery circuit is correct, IC804 is
replaced.
Check TR807 and the periphery circuit, and service it if
defective.
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