Rockford Fosgate replacement fets

[Steve]

I have a blown up Fosgate amp. The faceplate has been ripped off &
the model isn't anywhere on it, the best I can tell from images is it
is a Punch 401s. All four switching fets in the power supply circuit
are blown into oblivion. The only marking on one of them I can make
out is NTP45N (the rest of the number is missing). Any idea what fets
they use in the power supply side of these amps?

Also, what is the best way to go about removing & installing
transistors on those MESHA mounting brackets like shown in the
following link:
http://www.soundbuggy.com/Eric/Car Audio/rockford_fosgate/power_750x/DSC06696.JPG
Big soldering iron? Micro torch?

Thanks for any help,
Steve

 

[lmcclaf]

A few years back a friend brought me 2 of his Fosgate amps. One was a
40i or something like that and the other was a 200DSM or some such
thing (it's been a while since I looked at the docs I have). Anyway, I
emailed the company and they sent me the pdf files of the schematics.
Just in case the file I have for the 40i is the same as what you might
need I can always email it to you if you wish. Getting the transistors
off those rails was actually quite easy. I recall just removing a few
screws and then the whole rail would pull away from the transistors
and you could handle them with a regular 32W iron quite easily.

Cheers,
Lawrence

 

[Steve]

A few years back a friend brought me 2 of his Fosgate amps. One was a
40i or something like that and the other was a 200DSM or some such
thing (it's been a while since I looked at the docs I have). Anyway, I
emailed the company and they sent me the pdf files of the schematics.
Just in case the file I have for the 40i is the same as what you might
need I can always email it to you if you wish. Getting the transistors
off those rails was actually quite easy. I recall just removing a few
screws and then the whole rail would pull away from the transistors
and you could handle them with a regular 32W iron quite easily.

Cheers,
Lawrence

That's great news. I figured with it being designed to dissipate heat
the whole rail would suck the heat away. I'll have to give it a shot.
I'll have to email them and see if they'll email it to me.

Thanks,
Steve

 

[Mark D. Zacharias]

I have a blown up Fosgate amp. The faceplate has been ripped off &
the model isn't anywhere on it, the best I can tell from images is it
is a Punch 401s. All four switching fets in the power supply circuit
are blown into oblivion. The only marking on one of them I can make
out is NTP45N (the rest of the number is missing). Any idea what fets
they use in the power supply side of these amps?

Also, what is the best way to go about removing & installing
transistors on those MESHA mounting brackets like shown in the
following link:
http://www.soundbuggy.com/Eric/Car Audio/rockford_fosgate/power_750x/DSC06696.JPG
Big soldering iron? Micro torch?

Thanks for any help,
Steve

I looked at the picture and although I don't work on car amps anymore, I
remember ones that looked like this used a big aluminum bar laid across the
transistors and screwed down on top of them to secure them down.

Having said that, I would cut the transistor leads and pull them out
individually while heating with a soldering iron. You'll need the main board
out, of course...

Mark Z.

 

[Steve]

I looked at the picture and although I don't work on car amps anymore, I
remember ones that looked like this used a big aluminum bar laid across the
transistors and screwed down on top of them to secure them down.

Having said that, I would cut the transistor leads and pull them out
individually while heating with a soldering iron. You'll need the main board
out, of course...

Mark Z.

Most of the amps I've worked on work just like how you stated. On
this one, however, they solder the tabs of the transistors to the
board. You can see the extra pads on the side on the four corners.
They state it helps dissipate the heat beter than the traditional
clamp down bar on top. I have no idea which is better.

Thanks,
Steve