Rockford Fosgate Punch 500.2

[caraudioguy2100]

Are the MPSA06/56 the drivers for the outputs or where are the drivers located ?

200 series parts .

Amp will draw excessive current when trying to power up and the outputs get hot

 

[caraudioguy2100]

Rebuilt that channel .

I still have a problem with this amp .

As soon as I apply remote the amp draws excessive current .

The bias pots are set fully counter clockwise .

Any ideas ?

 

[seankane]

Which model of 500.2 is this?

 

[Perry Babin]

PC#s are needed on most Rockford amps.

 

[caraudioguy2100]

Here was couple pics including the board number

This was someone else’s attempted repair .

I rebuilt the 200 series channel but amp still draws excessive current

 

[Perry Babin]

It looks like D7 is blown. It's not causing the over-current but will cause engine noise.

Bias set to full CCW?

 

[caraudioguy2100]

Bias is set fully counter clockwise .

I replaced all of the smd diodes and transistors in that channel 200 series .

Checked every resistor in that channel as well .

That channel is still giving me
Issues with current draw

 

[Perry Babin]

Measure the DC voltage across all of the 0.1 ohm source resistors. Are they all the same or do you see higher voltage on some?

 

[caraudioguy2100]

They all remain at 0.00

 

[Perry Babin]

That's not enough resolution. go to at least 3 digits to the right of the decimal.

 

[caraudioguy2100]

I dont think it’s the channel causing the issue now .

I pulled the outputs from that channel and amp still draws 40 amps of current .

With the fet locations loaded with a 0.1 if cap here is what I get for drive signals .

Do these appear to look good ?

Also since someone tried repairing this them selfs .

Wondering if the regulators and rectifiers are in the correct locations ?

Like I said if I pull the outputs only the amp still draws 40 amps of current

 

[Perry Babin]

Those look OK.

The 3082 diagram I have only shows the output stage.

Compare your amp to the attached diagram.

 

[caraudioguy2100]

Ok I think the regulators may be in the wrong locations .

How do I determine which one goes where ?

On another amp the 337 sits next to the negative regulator in this amp it’s sitting next to the positive regulator .

But like I said the amp has been worked on before

 

[Perry Babin]

What is the voltage on the input pins? The positive regulator will have a positive voltage on the input.

I'd use new regulators if they were connected to the wrong rails.

 

[caraudioguy2100]

I replaced the power supply fets , regulators and rectifiers

The 317 has positive voltage on leg 3

337 has negative voltage on middle pin

Checked all of the outputs out of circuit and all test fine .

540’s are on negative rail 9540’s on positive rail

Amp still draws 40 amps of current when applying remote voltage

 

[Perry Babin]

Transformer?

Does it draw current with no rectifiers?

 

[caraudioguy2100]

If I pull the rectifiers amp doesn’t draw current

 

[Perry Babin]

Rail caps?

Reinstall one rectifier at a time to see if one causes the problem.

 

[caraudioguy2100]

I did some more checking

If I leave the rectifiers in when the amp draws excessive current the outputs in both channels get hot within secs

If I remove the rectifiers the amp will not draw excessive current

If I leave the negative rectifier out the amp will power up normally

 

[Perry Babin]

Is the source leg of the 9540s positive?