Keeps goin into protect HELP! (really found THE PROBLEM this time pg 6)

[Jared420]

dB-r Customer Service

06/29 14:17 The whole power supply was blown, and the reason was that 1 of the output mosfets failed, shorted out internally, common mode of failure for most any amp. Need to check your speaker wires with an ohm meter to make 100% sure you don't have a short somewhere, because that's usually what causes an output to fail. While you have the DMM on the speaker wire line, you also need to push in on the speaker gently to see if at any point it starts to read 0.00 ohms (shorted) because you could have a bad speaker. I am trying to located the output mosfets, noone seems to have them and they are obsolete, a substitute part IS likely availible that could even be better choice for this amp board than what was originally in it, but I am still researching it. I have already pulled all the power supply mosfets, rebuilt the drive circuit, cleaned up the board, and removed the bad output, I will need to replace the power supply mosfets before I can test fire the amp to make sure that the output drive section is still good, the amp should function with 1 output missing without a problem, unless the drive circuit (output drive circuit) got messed up when the output failed.

Since this is jibberish to me figured I would show you guys to see if this sounds suspect at all to anyone.

[tomypg]

Hmm, get some part numbers? Of the original and replaced parts? I'll go into my mates work and look them up.

[Boon]

dB-r Customer Service

06/29 14:17 The whole power supply was blown, and the reason was that 1 of the output mosfets failed, shorted out internally, common mode of failure for most any amp. Need to check your speaker wires with an ohm meter to make 100% sure you don't have a short somewhere, because that's usually what causes an output to fail. While you have the DMM on the speaker wire line, you also need to push in on the speaker gently to see if at any point it starts to read 0.00 ohms (shorted) because you could have a bad speaker. I am trying to located the output mosfets, noone seems to have them and they are obsolete, a substitute part IS likely availible that could even be better choice for this amp board than what was originally in it, but I am still researching it. I have already pulled all the power supply mosfets, rebuilt the drive circuit, cleaned up the board, and removed the bad output, I will need to replace the power supply mosfets before I can test fire the amp to make sure that the output drive section is still good, the amp should function with 1 output missing without a problem, unless the drive circuit (output drive circuit) got messed up when the output failed.

Since this is jibberish to me figured I would show you guys to see if this sounds suspect at all to anyone.

I can translate to laymans terms if you like... what he's saying there is all 100% normal.

He's saying that there was too much current through the output half of the amp, this was caused by either a speaker short or too low of an ohm load. One of the output MOSFETs blew up and turned into a short circuit. The power supply then has a short circuit across it, which caused it to blow up.

He's suggesting pushing your cones in when checking your subs with a DMM because if a coil is slightly misaligned or a former is warped it can rub at high excursion which causes the enamel on the voice coil to wear through and then the coil shorts out on the motor. Did you try this?

The guy saying that if your subs ohm reading changes doesn't know what he's on about to be honest. Take a brand new sub, put a DMM on it and push the cone, the impedance will change as the coil moves in the gap. It's called inductance. The tiny vibrations of your cone from air movement, nearby sound etc are enough to make the reading fluctuate slightly.

The bit in bold, he's saying the MOSFETs for the output section are no longer available. Probably replaced by a newer, better part so they discontinue the old one. Not a problem as long as you find an appropriate substitute. Often the newer parts are a lot better anyway.

The rest of it is standard 'your amp was smoked so I completely rebuilt the power supply'

Check and recheck your ground on the amp and rear battery. Hot headunit + flakey amp can be a sign of bad grounds, making the amp partially ground through the RCAs.

EDIT: Check the headunit's ground too. A lot of big amps like that will protect if the source is trying to ground through the RCAs as well.

[Jared420]

Thank you boon, you sir, know your shit. I will be sure to recheck my grounds again and checkout the rcas, my headunit is grounded just by the tiny wire that they give you to ground it with, just the black one that comes off the back. Is there a better way to ground it? Also, yes I did push lightly on the cones when I had my meter on them I checked all the woofers twice by doing that. Didn't see any 0's. I am still just so confused why I can play it loud when my voltage is low then turn it down let my volts get above 14 then turn it up and it cuts out.

[Jared420]

Just figured I would post another thing I found out. I hooked my amp up today to my friends Headunit with a different set of rcas and It protected again, I was at 14.6v. So I have eliminated 1. my HU 2. my rcas 3, Subs since when my volts are low I can play as loud as I want until they get above 14v. Basically leaving my alternator, grounds, or amp. Hopefully have time to check the alt and grounds tomorrow, If its not that I guess Im in the market for a new amp. Im not even really mad about it anymore. I gave dbr a shot they didnt work out time to just get a better set of amps.

[Jared420]

Just redid all of my grounds (clamped them as hard as possible even though they were all tight as hell, and went over my battery terminals, bolts, and ring terminals with sandpaper. Still went into protect, so I guess final test on the alternator tomorrow. If that doesnt turn out to be the problem, I am open to suggestions, What amp or amps should I get to replace this piece, Gonne take everyones advice and play it safe and run at 2 ohm so either a big amp that does power at 2 ohms or 2 smaller amps strapped at 2 ohms, Right now Im thinking I will get best bang for my buck going audioque , 2 2200s but Im open to suggestions.

[Jared420]

I got out of work early today so I decided to swap out my alternator and put my stock back it. Did it, Boom played full tilt in my driveway for about a minute. volts dropped down to 12 parked there but started at 14.6 and did not protect N8Ball you were right, I think. I am about to go for a ride to check it out for more than a minute and make sure this is fixing my problem but damn this was honestly the last thing I though it would be. Kinda bummed though cuz now I am going to have to contact Dom and from the look of the Irragi section doesnt seem like he has had the time to help people out lately. I know he's a good guy and Im not trashing him at all Im just bummed that it may take a while to get this fixed and I got my aq 2200s arriving TUESDAY! but Im going to take a spin and make sure I found my problem, Ill be back to update in a few. THANK YOU SO MUCH for all the help guys I really really do appreciate it

[skittlesRgood]

dont worry, youll get that alt fixed in about... 2-3 months lol.

[n8ball2013]

damn it feels good to be a gangster. glad you got it handled. We hope. now on to the nudie hair trick vids.

[Jared420]

Ok Now i feel like an idiot, sorry guys I should have waited til I got back from my ride around to test. Shits still going into protect, I really jumped the gun on that one. I think it worked in my driveway because my stock alt is so weak that the second anything happens my volts just drop like a rollercoaster. when i was driving they were holding a bit better so it was protecting everytime again. I got back to my house and tried it again in my driveway parked and it works. So i reved it up to 2000 rpm in my driveway and it cut out, so it really is when my voltage is lower it works.