Alpine MRV M500 Suddenly Stopped Working

Hi there,

I have an mrv-m500 that suddenly stopped working.
I checked the voltages with a multi meter and both the power and remote power cable are getting 12 volts the ground is ok and the fuses are ok. I replaced the fuse under the hood in case that was the problem but it was still the same. The sub is a 15in dual voice coil both coils are 4 ohm that I wired to be 2 ohm for the amp and both coils are ok. They are both at 4 ohm when I checked individually and at two ohm when I wired them back in parallel for the amp. The subwoofer is 500 watt max. I don't think this amp has a protect mode/light anywhere but the blue light that is normally on in the middle of the amp doesn't turn on anymore. Everything behind the head unit seems to be in order and right before it stopped working the light on the amp would flicker when I would first turn the car on then die off. The sad part is that it doesn't turn on at all now. I bought the amp only a year ago so I thought it was weird that it stopped working so abruptly. I took it to get checked at a shop but all they said is that the amp is fried and didn't bother to test or anything. I don't want to believe that it is fried at only a year and I also don't smell anything burned but they might be right. I was just wondering what someone else thought about the situation, thanks

does the amp smell funny? it sounds like your amp died, just like my alpine PDX died a while back. everything worked perfectly for over a year and then one day the amp just didnt come back on because a small transformer inside the amp somehow got fried along with some chips directly next to the transformer. no fuses were blown and the amp never went into protect, it just died.

How do you know the ground is good? When you checked voltage on power and remote wires, where did you have the ground lead of the meter?

Thanks for responding guys. Surprisingly the amp doesn't smell funny, but given all the symptoms I think it is indeed dead. I still want to take it to another shop and get it bench tested to be sure. What I did with the ground was when I put the positive lead from the multimiter on the power and remote wire I put the lead from the meter on the ground from the amp and also tried the unpainted part on the chassis where the ground from the amp is connected and also another unpainted part on the chassis and all three read 12 volts. I think I am just going to send it to alpine and see what they say.

I also read somewhere that the amplifier had "clipped" and I have no idea what that means. It said that to fix the clipping to switch the power and ground terminals (put the power into the ground and the ground into the power), take the fuses out and run the amp like that. That sounds very questionable and I don't want to try that. What do you guy think

I wouldn't try that if I were you.

yea i would not try switching the power and ground wire, that is a sure way to at least blow fuses or possibly destroy even more parts inside the amp. ive seen people do this on accident and it usually doesnt end well for the amp.

Yes, I thought so. Thanks for the help guys.

I had 4 of the m600's sold 3 and before I listed the last one I cracked it open just to see how they are made, first thing i noticed was the 2 main Caps were crowned! These are some big caps 6800uF 72v (If I recall correctly) but they're limited to the height of the amp which makes them really had to find replacements. From servicing other amps that have shown similar symptoms as your amp is, I'm willing to bet that the caps are bad in your amp. My amp was still working, (probably going to die soon), I replaced them before I would be selling it. Took a week of searching just to find a similar but not exact replacement that would fit into that space allowed. Had to modify how they mounted and they were covering a resistor which made them touch the bottom plate once reassembled. That amp ended up being the best sounding and loudest of them all. That tends to make me believe that the others were probably in need of replacement also but did not look to see. The caps ranged in price from $30 each (need 2 of then) and were not exact replacement size meaning diameter, height and lead spacing where not the same. They touched other components on all sides and had to be offset to fit, I was lucky and found 2 for $8 each, they were the only 2 that were available then. So if you're lucky enough to see this is your problem you'll have to hunt for those caps and probably end up spending about $30 minimum for 2 that may not even fit properly. Make sure to get as close as possible to the existing size caps to make the repair as simple as possible.
This is only my experience that I have encountered and by no means the only possible problem with your amp. This is how they will act when these go bad. They are the main Power Supply parts that will not allow the amp to power up when they go bad. It will be very obvious to see if they are bad, if they are domed or crowned up they could be part of the problem and a good starting point. I would show pics if I could but I think you get what I'm saying
Good Luck!

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20 crimped on wire splices is about perfect for a 10 foot run of wire (when it's installed by a "Pro" at the Car Stereo Shop)! LOL!