Denon DN-F450R, Service Manual, Page: 14 / 67

14
Check input level to fi rst stage amp.
b When setting Fs Ref=24dB at the reference input
level :
Bal
: [IC203 input] 0.775Vrms
Unbal : [IC204 input] 0.5Vrms
Check level from fi rst stage amp to the Unbal
conversion.
b Refer to LEVEL DIAGRAM .
Check input level to analog switch.
b Refer to LEVEL DIAGRAM .
Check input level to CODEC.
b
Refer to LEVEL DIAGRAM .
b Check that input of IC405 is not warped.
• [IC405] 51,52pin
Check parts (surrounding) and soldering.
Bal : First stage
π
type ATT constant
Unbal : [IC204] constant to input
and surrounding constant.
Check parts (surrounding) and soldering.
• [IC201,IC202,IC203] NJM2068
• [IC204]
NJM2068
• [IC205] BU40538
and surrounding constant.
Check parts (surrounding) and soldering.
• [IC205]
BU40538
• [IC207] BU40528
• [IC209] NJW1159
• [IC211] BU40528
and surrounding constant.
Check parts (surrounding) and soldering.
• [IC405] Analog input level
• Check input level of circuit on previous stage again.
N.G.
N.G.
N.G.
N.G.
3.2. Analog audio doesn't input
O.K.
O.K.
O.K.
END
O.K.