broken amp A2200HCT

[blockbeata09 3]

i have a audiobahn A2200HCT i had it pushin a dd3515 at 2 ohms half the power and one day i got in my car and turned the key over with out starting the car and the volume was on 7 as soon as the bass hit the amp popped 4 times all the lights work and the cooling fans it just dont make no noise ive takin it all apart and looked it over i cant find anything burnt up nothing smells funny i dont know what it is. i have some pics but i dont know how to post them on here thanks for your time

[blockbeata09 3]

Bump

[gerront 0]

hmmm check your rca output on your radio!! Run a different signal into the amp and see what happens....

[blockbeata09 3]

i replaced the amp with a hifonics bxi2608 and it works fine

[MTX520 0]

try getting new rca's...or try that amp with another headunit....my best guess would be the headunit thoug

[todd.brust 29]

Well in the case that the hifonics works fine, it's definitely the amp.

Just because nothing looks burnt doesn't mean anything. There's lots of things that could have gone wrong.

[emperorjj1 2]

ill buy it off your hands

[Adrian_D 520]

Just because nothing looks burnt doesn't mean anything. There's lots of things that could have gone wrong.

I completely agree. You may very well have the whole amp blown and not have a sign of smoke.

[blockbeata09 3]

i looked the amp over agian and found 4 transistors are cracked in half im just gonna buy 8 of them and replace the 1 side and hopefully thats the problem

[johnecon2001 82]

i looked the amp over agian and found 4 transistors are cracked in half im just gonna buy 8 of them and replace the 1 side and hopefully thats the problem

Let me caution you on replacing components internally on an amp unless you know for a fact, that they are the same parts.

If you have no prior soldering experience or circuit fixing experience.. I would pay someone else to fix your amp.

or, since it's an audiobahn....... I'd just buy a new amp.

[mdexxxiv 1]

Audiobahn amps are great for covering up cat-puke stains on your carpet. Keep it around.

[todd.brust 29]

Simply replacing the burnt up transistors may not be the fix. You could easily replace them with identical parts and turn the amp back on and fry the chit out of your new transistors.

They probably burnt up for a reason. Biasing resistors could be fried and just start saturation your transitors with current.

I'm with JohnE, pay someone to fix it.

[blockbeata09 3]

my uncle solders with a gun for a living and i typed in the model #on the transistors and found the some ones on parts-express.com irfz44npbf-nd i think i got it under control

[johnecon2001 82]

ok...

[95Honda 486]

Pay to get it fixed then sell it.

There isn't a single product made by Audiobahn that didn't have cosmetics as the #1 goal...

[Adrian_D 520]

my uncle solders with a gun for a living and i typed in the model #on the transistors and found the some ones on parts-express.com irfz44npbf-nd i think i got it under control

Soldering all your life and fixing amps for a living are 2 diffrent things.

Mosfets blow for a reason. When it's not excess heat it's some part in the control / drive section.

[emperorjj1 2]

i dont know if heat causes a mosfet to blow.. either way thou theres probably something else wrong in there too. I think ill withdraw my offer to buy the amp thou. most amps can be fixed but the possibility falls way down when someone "attempts" to fix it

[95Honda 486]

my uncle solders with a gun for a living and i typed in the model #on the transistors and found the some ones on parts-express.com irfz44npbf-nd i think i got it under control

Soldering all your life and fixing amps for a living are 2 diffrent things.

Mosfets blow for a reason. When it's not excess heat it's some part in the control / drive section.

I can't even tell you how many times on went on wild goose chases replacing semiconductors only to have them fail again 20-30 minutes later back in the day before I really understood this stuff...

Especially with Class D......

[Adrian_D 520]

my uncle solders with a gun for a living and i typed in the model #on the transistors and found the some ones on parts-express.com irfz44npbf-nd i think i got it under control

Soldering all your life and fixing amps for a living are 2 diffrent things.

Mosfets blow for a reason. When it's not excess heat it's some part in the control / drive section.

I can't even tell you how many times on went on wild goose chases replacing semiconductors only to have them fail again 20-30 minutes later back in the day before I really understood this stuff...

Especially with Class D......

I hear you on that one. Almost missed a comp because of that. Spent a day and a night trying to get my amp back into working shape and ended up borrowing a good amp

i dont know if heat causes a mosfet to blow..

Been there done that. In simple terms, excess heat causes a mosfet to act like a wire (shortcircuit) and it causes it to blow.

Viper 2500.1 at one ohm. Hot day, played music for 40 minutes, thermal protection was out for lunch. Amp was still hot 20 minutes after it blew. Blew the power supply mosfets and 2 power supply drivers.

[emperorjj1 2]

ya the amp getting too hot sure but i was talking about the part itself.

[95Honda 486]

Yep, they will absolutely fail with too much heat.... I built a Nalson Pass single-ended class A amp about 10 years ago and a fried a pair of FETs while seeing how much power I could get out of that design.... They fried from the heat alone of bias, there wasn't even music playing when they cooked...

And if you have bad drivers, you will keep replacing output devices. Also, matching can be an issue.... You get all kinds of wierd things here, especially uncontrollable DC offset on the output....

Come to think of it, the ONLY time I ever just replaced the output devices without checking anything else (and was succesful) was when I accidentally shorted the remote input to the speaker output connections (they are on the same barrier strip) on a PPI A600 about 15 years ago..... I knew excatly what I had done and that was the only reason the approach worked....

[Adrian_D 520]

ya the amp getting too hot sure but i was talking about the part itself.

The mosfets are actually the parts that get hot

[jonbearsmt 919]

did you have that amp screwed to your box/

[emperorjj1 2]

ya the amp getting too hot sure but i was talking about the part itself.

The mosfets are actually the parts that get hot

lol maybe i need to shut my noob ass up then... ive seen many blown fets in my time but i dont do any of the amp repair (just observe for fun) so im sorta just guessing. I wouldnt think they really get hot because the only ones ive seen that were broken either look fine or look like they exploded. Nothing like the plastic melted or anything of that sorts

[emperorjj1 2]

Yep, they will absolutely fail with too much heat.... I built a Nalson Pass single-ended class A amp about 10 years ago and a fried a pair of FETs while seeing how much power I could get out of that design.... They fried from the heat alone of bias, there wasn't even music playing when they cooked...

And if you have bad drivers, you will keep replacing output devices. Also, matching can be an issue.... You get all kinds of wierd things here, especially uncontrollable DC offset on the output....

Come to think of it, the ONLY time I ever just replaced the output devices without checking anything else (and was succesful) was when I accidentally shorted the remote input to the speaker output connections (they are on the same barrier strip) on a PPI A600 about 15 years ago..... I knew excatly what I had done and that was the only reason the approach worked....

lol reminds me of the ppi 2400 i have in my car. except i put the plug in backwards on accident