Did I Fry My Amp?

[Hemorrhage]

Hello!

I'm sorry if this is frowned upon, but this is my topic: www(dot)bimmerfest(dot)com/forums/showthread.php?p=7810345#post7810345

I wanted to get as many conclusions as possible on it. I figure this place would be more knowledgeable about the topic anyhow.

Thank you.

Click to read more...

 

[gckless 5,000+ posts]

Repost here.

 

[Hemorrhage]

Repost where?

 

[bbeljefe]

I didn't see anything wrong with the toroids in your picture. But, that's not what would have been hurt by shorting a speaker lead to the power input. You probably damaged the output FETS or possibly the power supply circuit.

Disconnect it completely from power for a few minutes and then reconnect it. If it still hums (that's the noise the sub was making) through the speaker output, then yes, you fried it. ... the amp, not the sub.

 

[Hemorrhage]

What would taking power away from it do, exactly?

Would it be different than just not turning the car on all night?

Also, I'm assuming it is safe to plug it back into the woofer, then?

I'm trusting you know your stuff.

 

[Hemorrhage]

View attachment 26544628

Also, I'm not sure what good this picture is for obvious reasons...but, if you guys need a closeup on something, let me know.

 

[Hemorrhage]

I took power away from the amp for ~5min, plugged the sub back in. gave power back to the amp, and it's still "humming".

Something else to note...

The "protection" light is still not on, even with the sub hooked up.

Is that bad?

 

[Hemorrhage]

Just some more information to help this ordeal...

I went over my friend's house (the guy that installed this all). He said the amp and sub are fine, but by shorting a speaker wire to power, I blew the head unit out of phase and blew the internal "PKO" fuse.

Does this sound correct?

 

[Side Show 10+ year member]

pico fuse problem = rca ground issue?

 

[Hemorrhage]

What do you mean?

I know my buddy took the RCA cables out from the back of the head unit and tapped them. The sub then stopped humming rapidly by itself. It only responded when he tapped the tip of the cable with his finger.

He said it has a ground loop because the pico fuse is broken.

Sound correct?

 

[Hemorrhage]

Anyone?

 

[ahardy17 10+ year member]

if it had blown a pico fuse in your HU you should be hearing terrible pops when you turn on and off. It happened to mine in a similar way. A live power wire contacted my rca's and boom, gone. A simple fix is to ground your rca outputs to your head unit by wrapping bare copper around all the rca outputs and securing it to the case of the HU. Your amp should be fine, on the bright side

 

[Side Show 10+ year member]

^^ do this, lots of images on the net of different ways this can be done

 

[Hemorrhage]

My friend did exactly that. He wrapped a wire around the RCA and did something. But still, the sub just "hums" and has no connection with the music.

The place I bought the head unit from said they will exchange it for a new one.

I just want to be sure it's a head unit. This whole ordeal has me confused, if you can't tell...

 

[hispls 5,000+ posts]

My friend did exactly that. He wrapped a wire around the RCA and did something. But still, the sub just "hums" and has no connection with the music.
The place I bought the head unit from said they will exchange it for a new one.

I just want to be sure it's a head unit. This whole ordeal has me confused, if you can't tell...

You can find the culprit with simple process of elimination. First unplug RCA's from the amp, if there is no noise it's not the amp. Next plug RCA's into the amp but unplug them from HU, if there is no noise your RCA cable is OK, if there is noise there is a problem with your RCA's (or where they are run). These 2 situations eliminated the only thing left is the source unit. If shorting the outside ring of the RCA's to the HU chassis doesn't help they you're in the market for a repair or new HU.