pca3500d in protection mode
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=83293
Printed Date: July 14, 2025 at 6:50 PM
Topic: pca3500d in protection mode
Posted By: makinwaves
Subject: pca3500d in protection mode
Date Posted: September 24, 2006 at 12:39 PM
I tuned a soundstream picasso 3500d to 77.45 volts with an 40Hz sine wave for running two dvc 2ohm digital design 3512c subs, which were wired with the voice coils in series and the subs in parallel. Within a half hour or so of playing with the new toy, it decided to go into protection, throw in alternator whine for a few seconds, and pulse the subs apparently in reverse excursion...I quickly shut everything off, but noticed this all as I was listening and observing the subs for tonal accuracy.
After removing the sub wires, and RCA inputs, the amp is obviously blown as it will not come out of protection mode. I happened to hear from someone about these brand new amps having a common problem with an internal component...and I was wondering if anyone is familiar with this situation. And is it a cap, diode, resistor, etc. Please elaborate, thanks.
makinwaves
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MakinWaves
Replies:
Posted By: i am an idiot
Date Posted: September 24, 2006 at 1:52 PM
Not familiar with your amp but 9 times out of 10 the protectioh light means you have shorted one or more output transistors. Hopefully it is under warranty. When returning the amp I would not mention the 40 hz sine wave. LOL
Posted By: makinwaves
Date Posted: September 28, 2006 at 8:04 PM
Just to clarify, when I used the sine wave, that was with no outputs, except the 10Mohm multimeter. Luckily, I do know better than that....lol. All I know is the amp sounded like it was getting DC voltage on the AC side, no smoke, nothing that would indicate a short, the voice coils were cool, and everything works fine with my old amp(temporarily). There is about 5volt input signal going to the amp. Even more, to ensure I had the proper power going to the amp, I turned on my headlamps while it was "pounding" about 143dB and the didn't dim at all, so without taking measurements there yet, I assume it had a minimum 12volts. Regardless, I already have installed a second battery with an isolator for the future.
Apparently, I must have received a faulty amp. Time will tell with it's replacement.
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MakinWaves
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