Uh-oh

[Sarthos 10+ year member]

I was driving my car and listening to some music kinda quietly then I heard a click. My volt meter dropped from like 13.5 volts (which is what my regulator keeps it at, stupid older car) to 11.9. It didn't go back up when I kicked down the gas so I decided to flip the switch and shut off my amps and stereo to save power because I thought my alternator just blew up or the regulator on it died or something. As soon as I flipped the switch my lights became bright again and everything seemed back to normal. So I flipped the switch again to turn my stereo and stuff back on, but I had no subs. I got home and checked and the light for my monoblock amp comes on saying it's on. I checked the ground and power and it has ground and power. I disconnected and reconnected the RCAs and tried another pair of RCAs and it didn't change anything. I've tried messing with the gains and everything but it seems to make no difference. Anyway, does anyone have any idea why my amp would turn on like its working, yet have no output?

Amp is Planet Audio RXD-2400

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[jco1385 5,000+ posts]

is it in protect?

 

[PioneerSPL1990 10+ year member]

outputs are fucked it sounds like?

 

[Mass Car Audio 10+ year member]

Sounds like the power supply has failed causing the amp to draw more dc current, the transistors in the PWM kinda control the current flow inside the amp, so when they fail the current get all mess up and will most likely try to draw more DC current to make up for the failed power supply fets and gates. If the amp is not going into protect then the over current protecting circuit is not working properly.

 

[Bobby322 10+ year member]

Hey, off topic but does your amp put out rated power?

 

[oxsign 5,000+ posts]

Hey, off topic but does your amp put out rated power?

Not anymore, lol.

Sorry, but I had an Mp do the same thing and it was the outputs that took a crap.

 

[cleansoundzz 10+ year member]

Low voltage is one of the biggest killer of amps around.

 

[Sarthos 10+ year member]

Why does everyone use italics and underlines and bolds to swear on this site? I know there's a swear filter but come on, there's also a Cyrillic alphabet on your computer. Look it up in the Character Map, there's symbols identical to "u" "c" "k" and some others.

Anyway no, the amp did not go into protect, the green power light came on. Thought I said that, apparently didn't.

So one of my friends and I took off the case and looked at the circuit board. a 2200 microfarad capacitor inside of it is bulged on top and there's some paper looking stuff coming out of it. So that's blown. But in another part of the amp there's some black soot along one of the sides where all the transistors are so I have no idea if any of them are blown or not. There's also one little part on the circuit board which appears to be partially melted, that looks like it might be easily replaced.

I'll take pictures in the morning, and there's a guy I kinda know who repairs amps but I'm not sure if he's up to the job or not. If not, who would the best person be to go to for getting it repaired? I'd hate to have to ship it to someone unless they do a really good job and can get it done. I can probably get pics of an identical amp with perfect internals, and I also might be buying another one so I could let someone see both to figure everything out...

 

[gunz4me 10+ year member]

I would be willing to bet your power supply went tits up.

As for getting it repaired, dB-r electronics is who I would recommend. He is one of the few who does things right the FIRST time.

 

[Mass Car Audio 10+ year member]

Why does everyone use italics and underlines and bolds to swear on this site? I know there's a swear filter but come on, there's also a Cyrillic alphabet on your computer. Look it up in the Character Map, there's symbols identical to "u" "c" "k" and some others.
Anyway no, the amp did not go into protect, the green power light came on. Thought I said that, apparently didn't.

So one of my friends and I took off the case and looked at the circuit board. a 2200 microfarad capacitor inside of it is bulged on top and there's some paper looking stuff coming out of it. So that's blown. But in another part of the amp there's some black soot along one of the sides where all the transistors are so I have no idea if any of them are blown or not. There's also one little part on the circuit board which appears to be partially melted, that looks like it might be easily replaced.

I'll take pictures in the morning, and there's a guy I kinda know who repairs amps but I'm not sure if he's up to the job or not. If not, who would the best person be to go to for getting it repaired? I'd hate to have to ship it to someone unless they do a really good job and can get it done. I can probably get pics of an identical amp with perfect internals, and I also might be buying another one so I could let someone see both to figure everything out...

the black soot is from the failed power supply or output transistors, and obviously that cap is no good either.