Denon DN-F650R, Service Manual

Page: 17 / 88

17
Check input level to fi rst stage amp.
b When setting Fs Ref=24dB at the reference input
level :
Bal : [IC202,IC203 input] 0.775Vrms
Unbal : [IC204 input] 0.5Vrms
Check level from fi rst stage amp to the Unbal
conversion.
b Refer to LAEVEL DIAGRAM .
Check operation of an analog switch.
b
Bal/Unbal switch
• [IC202,IC203]
Low → Bal
Hi → Unbal
b Stereo/Mono switch
• [IC207]9pin
Low → Stereo
Hi → Mono((L+R)/2)
Check operation of the electronic volume.
b Electronic volume level
• [IC209]9pin,10pin
When 1kHz 0dBFS is input
1.0Vrms
Check operation of the input selector.
b
Manual/ALC switch
• [IC211]10pin
Low → Manual
Hi → ALC
Check parts (surrounding) and soldering.
Bal : First stage π type ATT constant
Unbal : [IC204] constant to input
and other circuits.
Check parts (surrounding) and soldering.
• [IC202,IC203]
• [IC204]
• [TR201-TR211]
• [IC205]
and other circuits.
Check parts (surrounding) and soldering.
• [TR201,TR202,TR203]
• [IC203,IC207]
and other circuits.
Check parts (surrounding) and soldering.
• [IC208]
• [IC209]
b Factory default
and other circuits.
Check parts (surrounding) and soldering.
• [IC211]
• [TR208]
and other circuits.
N.G.
N.G.
N.G.
N.G.
N.G.
3.2. Analog audio doesn't input
(1) AUDIO UNIT
(2) MAIN UNIT
Replace MAIN UNIT.
O.K.
O.K.
O.K.
O.K.
O.K.