Rockford Fosgate Punch 500S

[Perry Babin]

Did you try pulling the center leg on the rectifiers to see if that reduced the current draw?

Do one at a time if you haven't done this already.

Are any of the transistors or rectifiers heating up?

Are the outputs still out of the circuit?

 

[seankane]

Did you try pulling the center leg on the rectifiers to see if that reduced the current draw?

Do one at a time if you haven't done this already.

Are any of the transistors or rectifiers heating up?

Are the outputs still out of the circuit?

I have not pulled the center leg of the rectifiers yet.

Only one channel has the output fets still in place the other channel has them removed, and there are no solder bridges.

None of the remaining output fets seem to be getting hot nor do the rectifiers.

So when I try to power up with the center leg removed of the rectifiers (one at a time) I should have the current limiting resistors not in line with the B+??

 

[Perry Babin]

Yes.

 

[seankane]

Powered up with center leg of CR2 removed and result was the amp would not power up.

Powered up with center leg of CR1 removed and result was the amp powered up fine and seem to have no issue.

Wierd??

 

[Perry Babin]

Was CR2 back in the circuit when you disconnected CR1?

 

[seankane]

YES

 

[Perry Babin]

If CR1 isn't leaking, I'd suspect a rail cap.

With NOTHING hooked to the amp, touch the 12v power supply across each of the rail caps (observing proper polarity). Does any cap cause any current flow after the initial charging?

 

[seankane]

The 3 on the CR1 side seem fine, but the 3 on the CR2 side arc pretty good when you apply power but none of them seem to be making my power supply draw current.

I removed one cap from the CR2 side and put power to it out of the circuit and it seemed fine holding 13.87 volts and slowly bleeding down.

Thinking CR2 is defective?

 

[Perry Babin]

I doubt that CR2 s defective if it powered up normally with it in the circuit.

Solder the legs for the rectifiers back to the board and disconnect the input legs of the voltage regulators. Does that reduce the excessive current draw?

 

[seankane]

I will try it.

Meanwhile I removed all the rail caps, and powered up the amp. It does not draw alot of current, but is a very choppy draw quickly pulsating up and down from 0 amps to 3 amps.

Shall I re-install the rail caps and try the voltage regulators next?

Can I power up the amp with the V/R input legs removed and the rail caps removed?

 

[Perry Babin]

If you have a couple of smaller caps (100uF or greater at same voltage as originals), install them (one in positive bank, one in negative bank). That should prevent the amp from surging. If it powers up normally with those caps, see if it will produce audio in the channel that has outputs.

 

[seankane]

OK the originals are 3300uf 50v I will see what I have.

 

[seankane]

I have a bunch of new 1000uf 50v I will try those??

 

[Perry Babin]

Those will be fine.

 

[seankane]

I installed one in each bank and it slowed it down a bit but still pulsing 0-3 amps up and down.

I dont get this thing.

Shall I remove the input legs for the V/R and see what happens?

 

[Perry Babin]

Yes. Both the positive and negative, one at a time.

 

[seankane]

Removed leg 3 input of LM337 and amp powers up fine no issues.

Shall I put it back in the circuit and remove leg 3 input of LM317?

 

[seankane]

Removed leg 3 input of LM317 and the led light came on but the amp didnt turn on. It drew nothing for current and the led light kinda flickered and the amp guage on the power supply was barely flickering up and down.

Input of LM337 was back in circuit for this test, do they both need to be out at the same time?

 

[Perry Babin]

When you say it didn't turn on, did you rely on the power LED or did you put a scope or meter on it to determine if the power supply was running?

 

[seankane]

I didnt use a scope or a meter. The LED light came on but the amp did not turn on like normal. I watched my power supply and when a amp turns on normal it jumps the amp guage up then back down and draws a little current at an idle. The amp guage was below zero amps on the guage.

If the power supply was running the rest of the amp was not on, I can tell when an amp turns on or not regardless of the LED.

I am not saying the power supply was not on but if it was the rest of the amp was not.

I will try it again and measure gate voltage on the power supply fets, rail voltage on the rectifiers, and output on the regulators.

Anything else you want me to check out?

Should I put the rail caps back in?