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Hey guys, yesterday while driving my speakers and sub cut out and didn't cut back in. I have a small system, two speakers and two subs. All connected to a Alpine MRP-550 4 Channel Amp. It's been working well for about 4 months now (minus winter when car was parked).

Well, anyways after my speakers and sub cut out. I decided to take a look at the amp and saw that the amp power light was dimming on and off. So I easily could tell that it wasn't getting enough power. So I checked my ground and fixed it and now my amp power light is solid and bright, so its getting enough power. However, I'm not getting sound out of my speakers or subs again.

I've checked the fuses, I tried plugging in my iPod into the amp with an RCA. Neither helped me figure out my problem. Any idea guys? I'm really hoping my amp's not toast.
 

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i installed a couple of these amps when i was working at tweeter. they are high power and a decent bit of distortion. i had 2 that melt polk momo crossovers and then **** the bed.
 

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definately a possibility. with the ones i worked with one of em seemed f'd up and it ended up being that it wasted all the speakers attached to it. either outlook is not good. where'd you get it and who installed it? If you can have someone check it out.
 

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I installed the system myself back in September and it has been working fine til now so I don't understand why it'd just randomly toast itself. The volume was fairly low when it stopped playing and the amp itself wasn't hot or anything.
 

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i would disconnect the speakers from the amp and meter them all. make sure the impedances are correct, if you have another speaker around hook it up loose to each channel to test them. if the speakers meter right but you get no sound from the extra speaker, then it could still be bad rca's or low voltage. meter the power and remote to see if the voltage is right. if it's right and still no sound. If you have an ipod or get an rca to headphone jack cable and plug it straight into the amp and play music. If you get no sound then, then your amp is most likely dead
 

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Well, I finally got around to checking my amp. I found a problem. The amp will be receiving 12.5 V when off, but as soon as I turn the car (and deck) on, it'll quickly drop to ~5 V. Any idea what the problem is?
 

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sounds strange but is the fuse under the hood glass? sometimes the solder goes bad, and as soon as they heat up contact is lost.
 

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when the car is running meter the power before and after the fuse holder. you'd see the drop there if the fuse is bad. if the voltage is good there and you meter it in the trunk on the amp and the voltage is ~.5v it is probably the ground is bad. when the car is off it might pull ground through remote or the rca shield.
 

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Well, I finally got around to checking my amp. I found a problem. The amp will be receiving 12.5 V when off, but as soon as I turn the car (and deck) on, it'll quickly drop to ~5 V. Any idea what the problem is?
Bad connection on either the power or ground leads. Quite likely the fuseholder, or fuse. Or could be a loose connection at the battery or even the amp. Check every junction point.
 

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Hey guys, yesterday while driving my speakers and sub cut out and didn't cut back in. I have a small system, two speakers and two subs. All connected to a Alpine MRP-550 4 Channel Amp. It's been working well for about 4 months now (minus winter when car was parked).

Well, anyways after my speakers and sub cut out. I decided to take a look at the amp and saw that the amp power light was dimming on and off. So I easily could tell that it wasn't getting enough power. So I checked my ground and fixed it and now my amp power light is solid and bright, so its getting enough power. However, I'm not getting sound out of my speakers or subs again.

I've checked the fuses, I tried plugging in my iPod into the amp with an RCA. Neither helped me figure out my problem. Any idea guys? I'm really hoping my amp's not toast.
if your ground was bad enough that your amplifier wasnt getting enough current.. then the pulse width modulated mosfet power supply would have had to work overtime to try and provide enough juice to run it,, this can blow the rail... or blow the power supply capacitors,,,

pull the amp apart and look at the rail caps.. see if they have exploded,,, if not,, then check the mosfets... it may just be a power supply problem
 
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