Rockford power 550???? unknown

[terminatore]

Rockford power 550???? unknown


hello I have an amp that has undergone a polarity inversion

I search the service manual

it's not a 550x

Thank you for your help

 

[terminatore]

with the photos it's better

 

[terminatore]

I try to put pictures! without success

 

[Perry Babin]

What is the PC# on the board?

 

[terminatore]

pc-3084c

 

[seankane]

Looks like a 500x 4 channel to me. The 500s was the 2 channel version. This is not a power series as the heat sink is black and it does not have 4 gauge power and ground terminals. The power series had grey heat sinks with an illuminated badge on top.

 

[Perry Babin]

To upload photos, please do it as follows in the future:

Go Advanced
Manage Attachments
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Repeat as necessary
Preview post to see how the post will look.
Click Submit Reply to send it to the forum.

~~~~~~~~~~~~~~~~

The reason I ask for a board number is because Rockford used the same board in multiple models. If you post the model number and I don't have anything under that model number, I won't find the relevant diagram which I may have under a different model number. As a side note, Rockford, in the past, has distributed diagrams for older amps if you email them.


See attached.

 

[terminatore]

Thank you for the info

the transistors are burned mtp75n05 irf9540 irf540 lm337 und u160r

on both sides

 

[terminatore]

Rockford Fosgate 400.4 (2001)
Output Power at 13.8V, 20Hz ∼ 20kHz:
4 x 50 @ 4 ohms (<0.05% THD)
4 x 100 @ 2 ohms (<0.1% THD)
2 x 200 @ 4 ohms bridged (<0.1% THD)
IM Distortion (IHF): <0.05%
S/N Ratio: >100dBA
Damping Factor: >200 (4 ohms)
Fuse: External 50A
Dimensions: 13.4" x 9.9" x 2.4" (34cm x 25.2cm x 6.1cm)
Manufactured in 2001, coded G14004
Credits: Thanks to Daniel de Ferrariis

 

[Perry Babin]

I think there may be a problem with checking those components. The rectifiers and regulators only very rarely fail. The outputs would not have been affected by reversing the B+ and ground connections.

 

[terminatore]

I check the whole list they are burned

1 irf540 c is decolled in the heat

I'm going to change everything and we'll see

 

[Perry Babin]

OK but the chance of all of those components failing due to B+ reversal is like winning the national lottery... twice... in consecutive weeks.

 

[terminatore]

ok Mr Perry Babin

I change which component first?

 

[Perry Babin]

When you connected the amp after making the reverse B+ connection, what happened?

 

[terminatore]

the fuse of 50a burns
the transistors heat up to death

 

[Perry Babin]

You need to be specific, give the circuit board designation, which transistors heat up (not all will heat up).

Measuring the resistance from leg 1 to leg 2 of all of the FETs (not the regulators, not the rectifiers), do any read lower resistance than the others with the same part number?

 

[terminatore]

I measure between 1 and 2

 

[Perry Babin]

Please re-read post #7 regarding posting images.

That diode is pin 2-3.

Just go check all of the components from 1-2 and compare between those with the same part number.

 

[terminatore]

measure right component to the left

mtp75n05 : 36 ohm
mtp75n05 :18 ohm
irf9540 : OL
irf540 : 4.2ohm
irf9540 : 24 ohm
irf540: OL

 

[Perry Babin]

Please re-read post #7 regarding posting images.

I expected you to check the components in the circuit. Any FET that doesn't read OL from leg 1 to leg 2 or 3 (out of the circuit) is defective.