Repairing Rockford fosgate punch 40X2 channel help

[chipper]

Originally Posted by mike49504

They are surface mount transistors for the drivers They are usually marked 1a and 2a set your meter to diode check and test them the same way as you did the outputs. Make sure you pull the bad outputs from the board before u test them.

Also the resistors you tested marked 100 are 10 ohm resistors if you have 11 ohms on 1 and 12 ohms on the other they should be fine

Okay gate resistors are off the list, may I ask what are typical readings for drivers transistors? And emitter resistors? .001 that's what i got when i checked them. They don't look burned or anything. Also I have donor RF amp that has good working IRF540s and IRF9540s. The power supply isn't fully working so that's why it's a donator amp (:. Thanks for all the help!

[brandes.cm]

They should read .1 ohms, you need to pull one leg out of the board to measure them. You may have something else shorted causing it to read low.

What does you meter read when you hook both probes together? You will need to subtract that from the measurement across the resistor.

[chipper]

What's the difference between IRF540 & "IRF540N" because I was browsing for some replacement MOSFETs and all I can is find irf540n's seems like they are the same type? Or can I use some from a donor amp? They still work on this donor amp. I also have a Punch 60x2 that I want to try a shot at. This one is burned up pretty bad. Also if try this can I use BUZ10 mosfets as the power supply?

[Perry Babin]

The IRF540Ns typically don't work properly in Rockford amplifiers.

If the ones from the donor amp are OK, there's no reason that they shouldn't work.

The BUZ10 isn't the best choice but they will work if you already have them. The IRFZ44 would probably be a better choice. Remember to check the gate resistors and the driver transistors.

[chipper]

Originally Posted by Perry Babin

The IRF540Ns typically don't work properly in Rockford amplifiers.

If the ones from the donor amp are OK, there's no reason that they shouldn't work.

The BUZ10 isn't the best choice but they will work if you already have them. The IRFZ44 would probably be a better choice. Remember to check the gate resistors and the driver transistors.

Hey!! It was a success! The amp played music nice and clear. But how do i set the bias? The left side gets a little warm so I'm not sure to set those.

[Perry Babin]

Do you have a DC amp meter on your 12v power supply?

[chipper]

Originally Posted by Perry Babin

Do you have a DC amp meter on your 12v power supply?

No I don't it doesn't have one it's just a 10amp 12volt powersuply. Could I use a vom?

[Perry Babin]

Yes. Can you get your meter probes on both ends of at least one 0.1 ohm source resistor in the channel that's running hot?