Another fried Kicker KX1200.1

[Perry Babin]

There's no N after 640 so you wouldn't use the N-version FET.

 

[olftboy]

Thank you sir. I'll get everything put back in and powered up and see what happens. I hope the next time I post it's a final THANK YOU on this issue. Your help has been invaluable.

 

[olftboy]

Okay, a little more help needed.

After replacing Q05 but before installing the new power supply FETs, measure the gate voltage on the gate pads for the power supply FETs. They should all read approximately 5v DC.

Replaced Q05 and measured gate voltage with power supply FETs uninstalled. Top side (near 12+ hookup) all read around 4.56 volts. Bottom side all read 12.78 volts. Does that mean I screwed up the Q05 install? It all seemed to go smooth and quick. The new Q05 readings all match the Q11 readings so I assumed it was good to go. Or... does this mean something else is toasted that I've missed.

Thanks.

 

[olftboy]

Went a little further with the troubleshooting while powered up.

Q05: (appears to feed the top side gate voltage which reads fine)
2-4.5volts
1-4.5volts

Q11: (appears to feed the bottom side gate voltage which shows 12+v)
2-4.5volts
1-12.6volts

So, I'm guessing Q11 is bad. Won't kill me to replace it so I'll do that and post back.

 

[olftboy]

Just a mini panic on my part. Replaced Q11 and gate voltage is back to 4.56 on the lower set. Going to work in the early early AM, so it will be next weekend before I post back some more results. (I'm sure you're waiting on the edge of your seat... )

Thanks again, guys.

 

[olftboy]

Thanks to all that helped. I now have a resurrected KX1200 pumping out tunes. Perry, especially, is responsible for my wife saying I was amazing. After which I showed her this forum and how I was walked through the repair. It was an amazing few minutes while my wife was proud of me, though.

In summary... bad components were Q05,Q11,R16,(8)IRF3205,(1)IRF640
I replaced Q05, Q11, R16, (8)3205's, (6)640's, (8)9640's