Rockford Fosgate punch 100x2

[chipper]

Hey guys I bought this 100ix or x2 for $40 came complete with side covers but my friend who also bought it didn't test it or knew if it worked or not I bought it because it's old school Rockford and I didn't test it as well I opened it because I was curious to see the guts I broke the warranty seals and I found a burned gate resistor upon my admiration of the guts so this leads me to thinking this channel is non functional. Can I just replace all four fets and source resistors, gate resistors and it'll be okay? Also can I change the original buz11's for IRF3205? Will that make any difference in it lasting longer? Thanks again guys!

 

[Perry Babin]

The 3205s can withstand more abuse. You need to make sure that the gate resistors are 51 ohms or less. Use 47 if the gate resistors need to be replaced.

Many times, when the source resistors open, the protection circuit is damaged.

Then the outputs fail, the driver stage is often damaged.

PC board #?

 

[chipper]

The power supply isn't blown it's all working. The original gate resistors are labeled 101. I'll make that upgrade I have 47 ohm resistors on hand too. I noticed R273 was burnt open The board number is PC-1090-A

 

[Perry Babin]

R273 is part of the protection circuit.

While the source resistors are out of the circuit (R276 and R263 need to match), confirm that R262 and R272 are within tolerance.

 

[chipper]

R262 - 152 ohm
R272 - 387 ohm

Does that sound right?

 

[Perry Babin]

No see attached.

 

[chipper]

Found the problem. There was a bad 2A transistor and a 390 ohm smd resistor was out of tolerance. Installed one of the good IRF540's that channel produces clean audio and biases. Should i replace the other two IRF9540's? They aren't shorted or leave them in?

 

[Perry Babin]

390 ohm or 39 ohm?

I would replace all of the outputs in this channel.