> I have a Rockford Fosgate amplifier, about 8 years old, and one channel
died and I
> need to replace two TO-220 transistors. The transistors are not bolted
directly to the
> heatsink, they are soldered to an intermediate PC board that has an
aluminum core. If
> you're familiar with heatsinked LEDs you are probably familiar with
aluminum core PC
> board.
> 
> I'm looking for advice about how to change these transistors. The amp will
cost about
> $300-$400 for a new one, plus a new model will need to be fitted to my car
which is a
> hassle working upside down in the trunk, so I'm willing to invest a couple
of hours fixing
> this one.


I did something like this a few months back, it was a motor control.  You
need to get a lot of heat into a small area as fast as possible.  No
worries!

I clipped the leads near the transistor body, and bent them straight.  I
don't have a hot-air rework station, but I do have a 2000W heat gun.
Nothing special, but I've made some attachments to reduce the ~30mm output
to something smaller (about 3 - 15mm).  The fan needed to be upgraded, of
course.

Grab the transistor with pliers, and hit the metal tab with the heat gun.
It should come off after a few seconds.  The leads you can get out with a
normal soldering iron.  Using the heat gun might fry the board.

Tony

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