Kenwood 9102

[mike49504]

Im working on a kenwood 9102d i checked the outputs and 2 were bad i took them out . The problem is the amp wont power on its completly dead wondering what i should check at this point since all the power supply fets test good

[Perry Babin]

With the amp powered up, what's the voltage on the 3 pins of Q3?

Q3
Pin 1:
Pin 2:
Pin 3:

[mike49504]

Perry ,

Didnt see Q3 i saw Q403 is that what u mean ?? if so

Pin 1= 0
Pin 2- 5.97
pin 3= 5.97

[Perry Babin]

See attached.

[mike49504]

Ok on Q3
Pin1= 13.90
Pin2= 4.72
Pin3= 13.30

[Perry Babin]

It's likely defective. If you have any TO-220 PNP transistor (2N6491, 2SAxxxx, 2SBxxxx...), you can use it to allow further testing. You'll have to install it facing the opposite direction because the pin configuration is reversed. The base goes to the nearest edge of the board.

[mike49504]

ok i replaced it with a 2n6491 and reversed it so now it reads

pin1=13.80

pin2= 8.18

pin3= 13.35


wondering what do i check neck since the amp is still dead i appericate the help perry without you id be lost

[Perry Babin]

The 13.35 is on leg 1 of the 6491 (ignoring the numbering of the other transistor), correct?

If so... is the 6491 getting hot?

[mike49504]

ignoring the pin order of the old transistor pin 1= 13.35

the 2n6491 is not getting hot at all amp has been powerd up for 10 mins

[Perry Babin]

What's the DC voltage on the 3 pins of Q2 (SMD under board - see attached for pin numbers)?

What's the DC voltage measured directly across R6?