question about transistors in kenwood kac-9104d

[usmcgrunt0331]

okay so my amps stuck in protection mode and so i opened it up and noticed a melted piece which 1 guy identified as a t0-220 transistor so i bought 1 and right after that a guy said thats not it and if i put it in itll do more damage than it already has if i put it in...he said its probably a stp60nf06fp n-channel mosfet....where can i buy 1 of these and how do i know its the correct part...please help asap! thanks in advance

[PedroDaGr8]

Originally Posted by usmcgrunt0331

okay so my amps stuck in protection mode and so i opened it up and noticed a melted piece which 1 guy identified as a t0-220 transistor so i bought 1 and right after that a guy said thats not it and if i put it in itll do more damage than it already has if i put it in...he said its probably a stp60nf06fp n-channel mosfet....where can i buy 1 of these and how do i know its the correct part...please help asap! thanks in advance

to-220 is a package type. It looks like this:
[image]http://chesterelectronics.com/images...loured_svg.png[/image]

to-220 is a VERY common package for mosfets because it allows for easy attaching to a heatsink. So saying you want a to-220 is kinda like saying you want an SUV, when you mean you want a honda cr-v.

Source for your fet:
MOSFET N-CH 60V 30A TO220FP - STP60NF06FP

[usmcgrunt0331]

so that bottom link is the suitable replacement for my blown transistor? sry if i sound like a noob but i rly am haha...jus wanna make sure i order the right part...dont wanna cause any more damage

[Perry Babin]

The 9104 uses 6 FETs in the supply. If one failed, all 6 must be replaced. kenwoodparts.com has the originals at $8.70 each. The 844-IRFIZ48GPBF at mouser should be a good substitute.

You need to check the driver transistors (Q13-Q16) as welll as the gate resistors.

The amp may have shorted outputs. You should check them before you order any parts.

[usmcgrunt0331]

what part number did u use at kenwoodparts 2 find that price and why would all 6 be replaced if only 1 failed lol...and which 6..i saw 14 transistors some bigger than others...i need 2 kno which 2 replace plz

[usmcgrunt0331]

also where r the q13-q16 and where r the gate resistors and how do i check the output things u spoke of..lol sry i kno i suck at life with this

[Perry Babin]

You need to do a bit of reading. Read the basic amp repair and the basic transistor testing pages (links below).

[mike49504]

Listen to Perry he knows his stuff.

Not to sound rude but if 1 power supply fet is shorted/blown you need to replace them all.

Here are a few reasons why.

1: All the fets need the same lot and date code If you only replace one of them you risk the chance of them not sharing the load evenly and the amp will breakdown again.

2: You only replace 1 of them and the amp goes out again you will be upset and have to order the parts all over again and wait for them to arrive.

3: If you only replace 1 of them and it shorts again this time it could take out other components in the amp making it unrepairable or not worth the time or money to fix it again.

Like perry said you need to check all of the power supply fets if 1 says its shorted others could possibly be leaking between the legs .

Also you ned to check the output transistors to see if any are shorted/leaking . If you have bad outputs and put new power supply fets in the amp it will blow all of the new fets again.

Also check the drivers for the power supply fets and the gate resistors in the amp.

Perry knows his stuff and is very smart when it come to amp repairs listen to him and your amp will be up and running in no time

[usmcgrunt0331]

okay i understand why i need 2 replace all of them but how do i know which 6 r the ones i need 2 replace?

[blakktalon]

Originally Posted by Perry Babin

You need to do a bit of reading. Read the basic amp repair and the basic transistor testing pages (links below).

read grasshopper.