# fixing nrv1507 alpine



## bass lover (May 2, 2011)

anyone have any expereance fixing these i already have the new mosfetrs but any help wuold be greatly appreciated


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## bass lover (May 2, 2011)

imeant mrv1507 great soundingamp


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## Notloudenuf (Sep 14, 2008)

I think Therum has done some repairs on this amp. Send him a PM to see.


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## bass lover (May 2, 2011)

yahe got a hold of me.Thanks man


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## Therum (Apr 18, 2009)

Which mosfets did you order?? The output section has IRF540 and IRF9540. The power supply section has IRFZ48N's i believe.


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## bass lover (May 2, 2011)

the 748ns two of them were deff gone.afew of them were burnt up.thenew ones should be here anyday


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## Therum (Apr 18, 2009)

did you check the output transistors? They are likely gone also.


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## bass lover (May 2, 2011)

no i will need help like i said im not to electronically smart butmydad is a wiz he can help.Do you know any one in ohio t that i could send it to?Maybe you?


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## Therum (Apr 18, 2009)

I will gladly fix it for you. but it "Should" be a easy fix. As long as it wasnt abused too bad.  I think that with alittle patience you can take care of it on your own. I know it looks like alot of stuff in the amp. But most of what you see most likely did not fail. But gotta start with the basics. Most of the time power supplies dont fail on their own. Unless the power and ground were hooked up in reverse, transformer shorts etc. But in the 1507 the transformers are wound pretty good and tight. So that is unlikely. The outputs DO fail from people abusing them. Like running it at 2 ohms mono. Like I said before I have experience with that one. LOL Lesson learned.  But checking the output transistors are easy. Check out Basic Car Audio Electronics and follow the instructions on how to do that. we will take it from there.


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## bass lover (May 2, 2011)

thanks therum.Just woke up and say your reply.ill do that and check the trasistors.Thanks for the helpfirsit gotto fix my space bar.lol I really wanttoget this fixed ive readthey sound great.againthanks for the help and youwill surly be hearing back.


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## Therum (Apr 18, 2009)

No problem. BTW where did you get the irfz48n's ?


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## bass lover (May 2, 2011)

mydad got themoff ebay. bad idea?ihadto get alot of ten then 2 single.ikn what brand any sugg.


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## Therum (Apr 18, 2009)

this is my 3rd reply to this thread. Hopefully this one gets posted.


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## Therum (Apr 18, 2009)

And it did. I prefer fairchild or international rectifier. But as long as they are made by an reputable manufacturer your ok. But I would caution you on fleebay since some of them can be fakes.


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## bass lover (May 2, 2011)

irsounds rite.Long day hellping me and my family move.Anywaydidnt getto theamp today cause allthe movin.ill keep ya updated,Thanks.OH ya also i have a broken old siver profile 1200 califonia.Yathink its worthfixn?


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## Therum (Apr 18, 2009)

Thats up to you. Depends on whats actually wrong with it. That should be easier to fix than the 1507.


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## bass lover (May 2, 2011)

Imgonna have to learn this stuff andstart fixing them.Itseems kinda fun.Or maybe a pain in the rear!


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## Therum (Apr 18, 2009)

Its fun to me. I do this in my spare time. But there are some pain the aces out there. The biggest,and my favorite, Xtants. No schematics available, no specific help available on the forums. Non traditional methods of getting things done. I guess thats why the sound so good. Other than brand specific, the biggest pain is getting an amp that someone else has been in. Thats the absolute worst!!  It makes things so hard to troubleshoot especially if they damaged the board. I have a 302a and a 403a that I am working behind someone that didnt know what they were doing. An 1001dx that is too far gone and a infinity 255a that came from the guys that "repair" amps for robot underground. That one is a mess. So the moral of my little rant. Yes its fun. Just be cautious when buying repair amps if this is what you want to do. Make sure that they didnt attempt a repair. If they did... offer half off their asking price and be prepared for some extended fun with the amp.


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## bass lover (May 2, 2011)

I got a new keyboard ha the pace bar works!Ya it looks like someone attempted to start to take the z48ns out to replace them and never did because im missing the clamps for them on one side of the board.Dad says he has some but hes getting old and who knows where they are?He is an electronic hoarder.Ham radio operator and a great dad.disabled cause of back.When i was younger he tried to tell me and teach me electronics but i just wasnt interested.Well now i am and hopfully we can do this togather.We just got forclosed on and are moving.Sorry i wrote a book


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## Therum (Apr 18, 2009)

Sorry to hear that. I can write another book on my opinion of mortgage companies and the ordeal one of my neighbors has gone through and how the banks are full of **** But thats another story. It worse comes to worse you can always buy some aluminum stock (Bar) and make your own. Do they still have the sil pads under them? Those are small clear "plastic" insulators that insulate the transistor from the heatsink. They are nessesary because the metal tab on the transistor has B+ (in the power supply section) on it and the heatsink is grounded. Verify that they are there and the tabs do not touch ANY metal at all. if they do and you connect power they will fail.


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## bass lover (May 2, 2011)

they are there.Man what a day!anyway my dad is supposed to help me do some work on it tommorrow.He has to bring the p.s and **** to start and check it.Speaking of robot underground i saw some of thier subs on ebay.All made with diff parts.what do u think about them any exp.


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## Therum (Apr 18, 2009)

I may open up a can of worms on this one. I dont think this is against forum rules. If it is Im sorry ahead of time. Here we go. I dont know about their subs.Nor do I have any real experiance with them. I have only bought that 255a from their "in house repair" guys and a set of PPI Plugs. BUT. If you search the classifieds he was selling some diamond mono amps that had cosmetic issues but they "worked". All had the serials removed. If you search flee bay you will see the same model amps, with the same pictures for sale for parts or repair. Also you will see his flawed method of measuring output of the amps. Anyone whom truly knows anything about car amps is that you cannot by any means rate an amplifier based on its fusing. For example, a KAC-PS200t as a fuse rating of 40a. the amp clips heavily at around 29a when driven into a 4 ohm load with both channels bridged. On the flip side. I had a sony amp, sorry i forgot the model number. But it was the xplod series , Maybe a 1004gx. Had 30a of fusing. The amp pulled 29a and wasnt clipping at all. That was with both sets of channels bridged into 4 ohms, clearly could have, in theory, been fused a bit higher.In Theory. So with the missing serials and horrible, misleading math I would not trust buying anything BUT ppi plugs from him. You cant F the plugs up. I think. Even with that I have found his supplier for his PPI plugs. Soon I will not even buy those from him.


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## bass lover (May 2, 2011)

thanks man. i need all the help i can get,So u say 2 12in skars will do good with the brutis 1200.Iwant the most spl possible but will sacrifice for sq.Thats wy i want this 1507 fixed.Just a ? wat aould u charge me to loook at it and maybe fix it if i give u the fets w it


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## Therum (Apr 18, 2009)

I dont know. $50. Thats me not buying any parts and obviously no return shipping. And thats also keeping in mind that I may not get to it until the weekend. I have no problems fixing the amp. But I think you can save your money and fix it yourself. Its not that hard I promise. it looks complex. And in reality. That amp is very complex. But, at least from the failures I have seen... and created... Its an easy fix. The most difficult thing to fix is the dang indicator circuits for the indicator lights. But even that took me only a good 10 mins of probing and schematic studying. Just to discover that 1 diode and 1 opamp failed at a cost of less than $2. But even with the stupid lights flashing the amp worked perfectly fine. So I dealt with it until it was time to sell it. But let me know. I'll fix it if you want me to. Or I can work you through fixing it yourself.


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## bass lover (May 2, 2011)

Thanks alot man you have bee a great help .Hopfully ill run into some more people like you. ill KEEP YA UPDATED


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## clipse4u2c (Nov 24, 2010)

I have a similar question. I have an alpine mrv-1005 which is just a model below and when I hook it up I get the green light and it does not go into protect. When I hook up the speakers I get nothing. So the amp has no output. I have replaced the amp and everything works fine so I know the problem is the amp. Any ideas on where to look. I took the back cover off and can't see anything that looks burt or blown although I'm not really sure what to look for other than the obvious signs. I amp isn't worth a whole lot so I don't want to spend alot sending it to get repaired. Any thoughts on what might be something to look into first. Thanks


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## Therum (Apr 18, 2009)

Read Basic Car Audio Electronics Goto amplifier repair basics. Hint. The power light being on means nothing other than remote voltage has been applied.  Hit me back after you have checked the amp. But check to make sure that the solder connections at the power terminal are still intact.


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## bass lover (May 2, 2011)

hey i have been so busy moving its driving me crazy.Any way that stupid old profile i was taking about has i think 6 big round caps and 2 feel blown.I only know this cause it happened to some of our computers and my dad showed me.I just might consider having you help me when u can therum on this alpine.I just have no time !!!!


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## bass lover (May 2, 2011)

i need help knowing how to check some stuff i got a good meeter im goonna go to bed.


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## Therum (Apr 18, 2009)

So hows it going?


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