Rockford P1000bd

[seankane]

This amp powers up and is stable. It has regulated and rail voltage.

The rail is not making it to the outputs.

I am suspecting this card. Is the little LED light on this card suppose to be lit when the amp is on and working or is it suppose to be off?

This amp has no DC on output terminals. This amp is not in protect.

This amp has no audio output??

 

[DigitalJunkie]

LED? You mean the black thing at the top? That looks like an LDR -an LED and photoresistor in one package. No,it should not light up.
I could be wrong.

 

[Perry Babin]

That's right. It's an LDR and it doesn't produce any visible output.

Do you have rail if you measure between the center legs of the rectifiers?

Are you sure that you don't have any continuity between the center legs of the rectifiers and any of the drains/sources of any of the outputs?

 

[seankane]

I was not talking about the LDR I was refering to the smd LED beside it. It is in the shadow and hard to see.

I will check the measurements again.

 

[seankane]

D291 sure looks like an LED to me.

 

[Perry Babin]

I don't remember that LED ever being lit. I think it may be part of the protection circuit.

 

[Perry Babin]

D291 is an LED.

 

[seankane]

Ok it was not lit when the amp was powered up, thats why I was asking. I just saw it and figured someone would know, and that would help me eliminate problems. The input is not making it to the outputs.

I guess I should re-install the card and test other things?

 

[Perry Babin]

There are 4 large SMD transistors just behind that board. Do they appear to have overheated?

Is the board warped under them?

 

[seankane]

MJD44H11?

Somebody has either replaced them or reflowed the solder on them.

There is alot of solder on their pins.

Not sure if its safe to power up with the bd output board not installed.

Another member told me to replace those and there are usually a couple of LM6172's fried. The LM6172's are on the bd output board. I was thinking to replace them and then re-installing the board and going from there.

What do you think?

 

[Perry Babin]

I've never seen anything fail on the board that you pulled. The regulators (those 4 transistors) are the biggest problem with these amps.

R9 sometimes breaks loose from the board but only when it hasn't been siliconed to the capacitor.

R2035 sometimes has bad solder connections.

 

[seankane]

I dont know if they have been replaced there are 3 MJD44H11 and 1 MJD45H11. I just noticed lots of fresh solder on all of their pins.

R2035 has been resoldered to the board as well.

R9 did have one end broke off the board and it was burned brown, it reads 30 ohms and looks like a 5 watt flameproof. Not sure if that is OEM or it should match the white ones. I am not sure of its true vale but it reads 30 ohms.

 

[Perry Babin]

It appears to be 30 ohms in the photos I have.

 

[seankane]

It gets super hot and has turned brown.

What effects could it have on the amp not being hooked up at one end?

 

[Perry Babin]

I think it feeds the regulators that get hot.

 

[seankane]

Ok how do I know if the regulators were replaced that they were installed correctly as in the right locations?

Do you know if 3 locations had the MJD44H11 and which one had the MJD45H11?

 

[Perry Babin]

This is a T1500. Are they the same? If not, maybe the designations are the same.

 

[seankane]

They look identical, the amp I have has them in the same locations.

So if they were not replaced and just resoldered they could be bad and this can cause no output?

 

[Perry Babin]

It's possible but you can check the output from each one to see if the transistor is in good condition. Did you solder R9 back into the circuit and reinstall the board?

 

[seankane]

Not yet. There is not enough left sticking out of the bottom to resolder it. It broke off flush. The only 5 watt resistors I have are .27 ohm, .47 ohm, and .1 ohm and none of those are close.