im an installer at cc so heres my story.
so my avic n1 smoked recently. i was driving, hit the brakes really hard, heard some crackling from my speakers, and the n1 smokes. fuse on the back of the unit smokes, and back up fuse for the car smokes. had no idea why avic smoked.

so the n1 is sent out for warranty repair.

i have 2 amps, an spl 2ch for subs, and a directed 350 for 4 speakers.

i purchase an alpine cd player to listen to while the n1 is out for repair.
i hook up the deck and the speakers make weird loud noises, high pitched etc. and i see a little smoke come from the deck, i quickly turn it off. my more senior coworker tells me the amp is bad, we unhook the rcas from the amp thats powering the interior speakers and the deck/subs work fine. he says that my amp is bad, probably had a surge when i slammed on the brakes before, messed up the amp, backfed thru the rca's/remote turn on and fried the avic.
but the green light is still on the amp, no fuses burned, no red light, nothing. but its still bad? because everything is all messed up when the rca's are plugged in.

so basically, that bad directed amp could backfeed thru rca's /remote turn on and fry my head unit(the previous avic n1) ?

 

I would check the RCAs, put a multimeter on them, check for short or power on them, [ with thm pluged into the amp] then unplug them from the amp and check them again. 94

 

arent rca's supposed to have a low signal? bad rca's will cause a head unit to fry?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by so simple &raquo;</TD></TR><TR><TD CLASS="quote">arent rca's supposed to have a low signal? bad rca's will cause a head unit to fry?</TD></TR></TABLE>Yes they carry a preamp sig. from the HU to the amp, there are a few things that can go wrong with RCAs 1- a short between the sig. pos., [ the center pin] and sig. neg., [ the outside part of the RCA plug] 2- a short to ground of the sig. pos., [ same as 1 but shorted right to cars chassis] 3- something in the amp went west and sent 12v+ up the RCAs to the HU 4- the ground on the amp "lifted" and the amp trys to get a groung through the RCAs, and you burn the sig. neg. tracers on the PC board in the HU lots of smoke and the speakers would sound ugly, [no sig. ground] also would happen as soon as you turn on any other HU pluged into that amp. 94

 

It's kinda doubtful but possible. Something would really have to go wrong for the amp to send a DC signal back up the RCA's. Most inputs have a capacitor in series with the input (internal to the amplifier). A capacitor looks like an open circuit to DC but a short for AC. This is why your AC signal can get through. Something more than a surge would need to happen for the cap to go bad. So take out a multimeter connect the amp up on your bench turn it on test to see if you get a DC voltage out of the RCA input.

This caps serves a couple of purposes. It will prevent DC from getting in the amp. It will also prevent any bias voltage from going out the amp. It won't trip any circuit protection because the voltage is supposed to be there. The cap is just suppossed to prevent it from getting out. I would be surprised if this is it but try it.

 

i tried to check the rca's with a multimeter but didnt really know what i was looking for, um, it wasnt showing 12v, which its not supposed to anyways. but i changed the rca's to a new set and the amp worked fine. so did bad rca's burn my avic?