Kenwood Kac-8104D Problem

bigpun4fubu · 2011-11-12 9:07 pm

i removed Q409 and put board back in case and powered it up and the red light now comes on It is NOT in protect anymore I cant seem to read the markings on Q409, would you know what the part number is and should I replace the outputs or do you think they will be ok?

bigpun4fubu · 2011-11-12 9:11 pm

i get a steady 1.143 vdc off the speaker terminals now

Perry Babin · 2011-11-12 9:23 pm

Did Q409 read ~330 ohms out of the board?

It's a 2SB1427.

bigpun4fubu · 2011-11-12 10:22 pm

not sure it was 330 but it ill check again in a lil bit

bigpun4fubu · 2011-11-13 1:33 am

seems to check good out of circuit do these diode check the same as the fets?

bigpun4fubu · 2011-11-13 1:35 am

well maybe not ohms check at measures 27 mohms but its dropping gradually so i assume leakage

Perry Babin · 2011-11-13 2:47 am

The components that you checked were bipolar transistors, not diodes.

27M ohms between which legs?

Did you check it on diode check?

When you read a 'short' on the board earlier, did the meter read near 0 ohms?

bigpun4fubu · 2011-11-13 3:41 am

legs 1-2 i checked it with ohms when i checked it in the board it was reading 330 ohms same legs 1-2

Perry Babin · 2011-11-13 3:46 am

What has changed to make it read differently now?

bigpun4fubu · 2011-11-13 3:50 am

im not sure , its really tiny and was hard to get a good solid connection off the board with the probes on the meter

Perry Babin · 2011-11-13 3:53 am

Did you check the transistors on diode-check?

If so, did you confirm that all transistors had two good junctions?

bigpun4fubu · 2011-11-13 3:55 am

i did that yes

bigpun4fubu · 2011-11-13 4:16 am

q409 is checking .6v black probe on leg 1 and red on 2 get OL both ways on legs 2-3 diode check

Perry Babin · 2011-11-13 5:27 pm

Go to the basic transistor testing page (link in sig line below), find the surface mount section. Follow the directions and post the reading for both resistance and diode check and post the screen cap of the filled form.

bigpun4fubu · 2011-11-13 5:49 pm

its just displaying a blue page

Perry Babin · 2011-11-13 5:59 pm

You should have seen what's shown below.

bigpun4fubu · 2011-11-13 6:46 pm

Perry Babin · 2011-11-13 6:50 pm

That transistor is OK.

bigpun4fubu · 2011-11-13 6:51 pm

bigpun4fubu · 2011-11-13 8:04 pm

ill put it back in and see if it goes back into protect

Kenwood Kac-8104D Problem

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