Rockford Fosgate Punch 250M2

[caraudioguy2100]

Anyone have a schematic for this amp?

Someone has been inside it before and I saw a lot of wrong parts already .

 

[Perry Babin]

When asking for Rockford diagrams, it's best to give the PC#.

http://www.bcae1.com/temp/rockford - power250m2.pdf

 

[caraudioguy2100]

What power supply fets would you use in this amp ?

The originals were MTP50N06

Z44’s or 3205’s?

 

[Perry Babin]

3205s

 

[caraudioguy2100]

Do you know if this was done at the factory or someone’ else’s mod ?

A cap between R20 and and pins 9 and 10 of the lm339

 

[Perry Babin]

Is it connected like C10 on the diagram?

 

[caraudioguy2100]

Ok now I see it yeah it connects like C10

 

[caraudioguy2100]

The original gate resistors are 22 ohm .

I’m gonna use 3205’s in the power supply .

Since I don’t have 22 ohm resistors on hand and trying to finish this amp is there another value I can use ?

 

[Perry Babin]

Do you have any 47 ohm?

 

[caraudioguy2100]

Yes

 

[Perry Babin]

That's what's most commonly used with 3205s.

 

[caraudioguy2100]

Is there a reason that both leads are not soldered to the board on this thermistor ?

It appears to have never been soldered even from the factory

 

[Perry Babin]

It looks like a factory defect but it's odd that the via isn't filled.

 

[caraudioguy2100]

I forget which 2 diodes do I lift to disable the protection in 1 of the channels ?

300 series parts

 

[Perry Babin]

D303 and D304, maybe.

I've never tried in on one of these amps. Be careful.

 

[caraudioguy2100]

Lifted both 1 at at times no change .

I will have to go through the channel to figure out why it has distorted audio and won’t bias

 

[caraudioguy2100]

Is there an easy way to check the components like voltage wise or do I have to ohm everything out I’ve went through the channel and everything is testing good but I know a transistor or resistor is bad or both . Since I get very distorted output and e channel will not bias

 

[Perry Babin]

Inside the feedback loop, one bad component can cause the voltage on all other components in the loop to be off.

When checking transistors, what are you checking?

 

[caraudioguy2100]

I’m checking the 2a’s 1g’s 2g’s ect that are one that channel

 

[Perry Babin]

What are you checking the transistors for besides shorted junctions?