Power Amplifier Ic Replacement - Yamaha YHT-196 Service Manual

HTR-2064/NS-B20/NS-C20/NS-SWP20

■ POWER AMPLIFIER IC REPLACEMENT

In the middle of production, the power amplifier IC has been changed from Y type to N type. At the same time, their
peripheral electrical parts also have been altered.
Y type: Parts No. X8190B00
N type: Parts No. YD936A00
Therefore, when replacing Y type with N type, their peripheral electrical parts also MUST be altered at the same time.
Replacement procedure
Perform the following procedure according to the type name of installed power amplifier IC.
Top view
1
16
STK433-330Y-E
STK433-330N-E
Y
STK433-330
19
Fig. 2
Initial production
Middle production and after
Service replacement part
IC1 IC2
Fig. 1
When "Y" is printed
<IC1>
Remove C25, C29 and C33.
Replace R23 with 4.7 k-ohms.
Replace IC1 with N type.
<IC2>
Remove C24, C31 and C34.
Replace R25 with 4.7 k-ohms.
Replace IC2 with N type.
When "N" is printed
Replace IC1/IC2 with N type.
Rear side
MAIN (1) P.C.B.
Front side