Rockford Fosgate power 300 mosfet

[chipper]

Got a power 300 with a bad power supply. One buz10 went bad when I applied power and remote. Is there a reason for that to open? And what’s direct replacement for buz10? Thanks!

 

[chipper]

Here’s the board

 

[Old'n'Cranky]

Looks like a hell of a lot of corrosion throughout the board.

 

[Perry Babin]

Assuming that there were no problems in the audio section...
heatsink coating failing
age (most likely)
bad connections on the gate terminals of one of the PS FETs
shorted rectifier or transformer

Replace the FETs with more modern FETs. The IRFZ44 with 100 ohm gate resistors should be good enough.

 

[Josheep]

Hi guys much the same problem, one buz10 is toasted. I didn’t apply power, it just came to me like that. I just wanted to check how the IRFZ44 worked out for you chipper, and Perry when you say 100ohm gate resistors I haven’t found a schematic so without wanting to sound like too much of a muppet which resistors on the board are they?

 

[jkrokenberger]

I used these as direct replacements for BUZ10's and had good success without changing the gate resistors. From this seller also. Some sellers send authentic parts, some don't - I got good parts from this seller.

Harris N-Channel Power MOSFET, 50v, 25A - Lot of 10 | eBay

 

[jkrokenberger]

The parts I linked to are similar in spec to the BUZ10 so don't expect any more out of them. The IRFZ44 is a stronger part and will be more reliable but takes the added work of changing the gate resistors.

So long as the work is done well and the amp is given good electrical with a load it was designed for you will have no issues with either.

 

[Josheep]

Thanks jkrokenberger, gutted that that’s a US seller as I’m UK based. I’m not after anything extra just to get the thing running (without compromising the sound it would already of had), I’m happy to build in some extra resilience though so if you/anyone knows of a schematic or could point me in the right direction I’d be well happy to change the resistors and stick in some IRFZ44’s.

 

[Perry Babin]

Please don't post in a repair thread that was started by someone else unless you are trying to help them.

Start a new thread.

 

[Josheep]

Please don't post in a repair thread that was started by someone else unless you are trying to help them.

Start a new thread.

Apologies, will do. Got a bit overexcited to see the same fault and jumped on board

 

[SomeGeoffGuy]

Did you recap it? Seems like those electrolytics are looking a bit rough.


-Geoff