stupid amp problem

[udmsvt]

ok, before i get flamed, i have had several systems in previous vehicles and have had this one in my ex for a while....nothing huge, just a 600watt amp and a 12.

here's my problem. i was bumping down the road tonight and my amp just cut out. so i pulled over and left it running. i check the amp and it still has power but insted of the bolt being lit up, the "protection" light is lit up. i check the lines and my line for the remote was loose so i fixed it. i check the underhood fuse and the fuse on the amp and all is ok.

so i turn the truck off and back on and the amp comes back on, but if i turn the HU past a vol level of 8 (its a pioneer, usually is at 20, max is like 60)...the amp goes back to "protection". mind you, i had just left a restraunt like 5 min prior and it has a fan on it and it has NEVER overheated before....so what's the deal? i can turn the radio off and back on and it will work...until i turn the radio up. i checked it and its still getting power and a signal. the only thing i could think of is a wire inside the box came loose and when it bumps, it grounds itself out....but why would it work at all?

anybody got clues? if it wasnt almost 1am, i'd pull the sub out and take a look but that will wait till tomarrow.....IF there are any more problems. i just want to know what the heck happened and what that "protection" light means.

 

[wired_af]

hmmmm...this is no help....but my friend had the same problem with an amp goin into protection mode.....that was along time ago and he ended up gettin a different amp.

 

[udmsvt]

oh, not the news i wanted to hear. dont get me wrong, i could pick up another one cheap (or just get a thunderform ) but i bought this one new and have loved it....its perfect for what i use it for.

i still want to know what the heck happened!

 

[Redrig]

my guess is your amp is done. i think when the protection light comes on it means your overdriving it. and something happened to yours and now it can handle what it is supposed to.

 

[wired_af]

but it might just be a simple wiring problem.

 

[udmsvt]

well, i did have it up louder than normal but i dont get it. i have never (nor has anyone i know) had an amp go bad. i'm hoping that when i fire up the truck in the morning, all wil be well but that still leaves me with "what happened?" and if its toast, why dould it still work a little?

i have a pioneer premier deh740mp HU w/ 4v preouts, 4 ga cable straight back w/ a 60 amp fuse inline plus whatever they put in the amp. it is only a bolt 200.2, so it really shouldnt draw that much...its only like 200wrms (bridged)

 

[udmsvt]

Originally posted by wired_af
but it might just be a simple wiring problem.

could be. all the wires i can see seem fine. power/ground ok. remote fine (at amp) rca's fine (at amp) speaker connection to box ok. only other wires are remote at HU, RCA at HU and speaker in box...i will check those tomarrow if problem persists.

 

[wired_af]

protection lights usually come on for a few reasons like:

short circut protect - in case you attach say, a 1ohm load to a 4ohm stable amp. amp will just turn off and not fry itself,

reverse bias proteciton - in case you plug the amp in backwards! protects the input caps and other things that would blow up if attached backwards.

Thermal overload protection - things get VERY hot inside the amp, well over 120 degrees. however the amp is made to shut itself off if it's TOO hot. amplifers using regualated power supplies often get VERY hot if you have a weak battery/alternator or thin/long power wire.

usually you can fix this by checking the impedance of the load to see if the amp is stable at said load, by moving the amp to a location where it can cool easier, by upgrading wiring/battery, or by reducing gains.

 

[udmsvt]

been running this setup for almost a year (minus the fan) and this is the first time. havent changed anything since i first set it up.

 

[udmsvt]

PROBLEM SOLVED

ok, i feel dumb.

i did some testing and figured it out.

first, i unhoked the speaker wire from the back of the box to test to see if the amp was shorting. cranked it and no problems with shutting off. then, i touched the speaker wires together and it went into protect, so now i know what it does. so i hook it back up and test, still shuts off. so i know its inside the box.

i take the cover off (q-logic box) and pull the sub. all connections are fine, but just to be sure i re-do all of them and re-test. same thing, only works on really low volume, but i can hear a pop at the sub when it shuts off, so i assumed that the sub was shorting out.

so, i go to meijer and pick up a $30 sub, take it out to the truck and swap it in, and crank it.....works perfect! (and sounded pretty good for a $30 sub!) so i pack it back up and return it.

my conclusion: the sub may not necessarily be blown, but it shorts itself out and i cant see where so i am not going to attempt to fix it.

how did this happen? well, my best guess is:

1) amp rated @ 600w max (though i never dreamed it would peak)
2) sub rated @ 500w max
3) amp made by rockford fostgate (usually under-rates their amps)
4) borrowed a CD from a buddy and was blasting Bone.

solution: MTX thunderform 10"....started shopping today.

 

[mhn3773]

so it was the sub.....damn i thought my amp blew my sub when that same thing happened one nite...ill bet the sub just blew i took the sub back to bestbuy and i had another amp but the other amp i had blew the new sub so i took the sub back all together...now i have no boom boom waaaaahhhhhhhh! lol i need to make an e bay run

 

[udmsvt]

beleiev it or not, i am considering buying that $30 sub i used to test my system form meijer...it dounded pretty good for the price..but i do have my heart set on a stealth setup now. this fiasco was just the kick in the butt that i needed.

 

[93lx12s]

thats what happened when my friend blew a sub a few years ago. it was an older sony amp. If he kept it down low it would work but when he wanted to bump the amp would cut it out and go into protection mode.

 

[udmsvt]

it just craks me up....its a little Lightning Audio Bolt 200.2 amp, rated at 600 max (which i doubt it will ever do!) and the sub was a mid-level pioneer rated at 500w max. i have put over 600w to one of teh lower pioneer before and never had a problem. then again, bolt is a division of RF...and they do tend to under-rate stuff.

the real kicker is, now i have a problem with my 6x8s too! i am running on only 3 speakers, and i know the 4th isnt blown.