Does my amp work?

[Ginkosu]

Hey guys, I have a 2-year-old Crunch 1000 watt amp that i believe has stopped working. One day it just stopped! So I bought new rca cable ran it from my kenwood head unit and still nothing. So I took my iphone hooked it via rca adapter to my amp and no response from that either. the amp is on but no sound, no protection light either. I have checked and re-checked evry fuse I could, they are all fine. Im prepared to buy a new amp just want to know if there is anything else I can do.

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[Kangaroux 5,000+ posts]

do you have a multi meter?

 

[mikelaubach 10+ year member]

Something inside went "poof!!" I had an older amp that died, and having an electronics background (adn still having the proper tools), I tore into it to see how it ticked. I found that there was a bad solder joint that opened up. The amp did exactly as you describe - turned on, green LED lit, but no sound.

Turns out the solder joint prevented the upper voltage to the rail, and the transistors cannot turn on because of that. Therefore, no sound. I did have to trace the lines and find the voltage, then find where it disappeared before i found the bad joint. It was NOT something I would have ever seen with the nekkid eye.

Might be worthwhile to find a local electronics repair shop and see if they can fix it.

 

[mikelaubach 10+ year member]

do you have a multi meter?

My fix required a o-scope to trace the square wave out of the power supply. A DVM/DMM might be a start, but might not get the job done.

Also, the probes are generally large, whereas a scope has an incredibly small, pin-like probe. this allows you to get into the transistor legs without shorting across legs and causing other issues. So just be careful to stay on the leg with using a DVM/DMM.

 

[Kangaroux 5,000+ posts]

My fix required a o-scope to trace the square wave out of the power supply. A DVM/DMM might be a start, but might not get the job done.Also, the probes are generally large, whereas a scope has an incredibly small, pin-like probe. this allows you to get into the transistor legs without shorting across legs and causing other issues. So just be careful to stay on the leg with using a DVM/DMM.

i wasnt even gonna suggest using the dmm inside i was going to say to check the outputs

 

[Ginkosu]

I dont have a mulit-meter, but they are pretty inexpensive, right?

 

[Kangaroux 5,000+ posts]

I dont have a mulit-meter, but they are pretty inexpensive, right?

depends what you buy. the really nice accurate fluke ones can be 200+ but you can get a cheaper one for like $60

 

[Ginkosu]

depends what you buy. the really nice accurate fluke ones can be 200+ but you can get a cheaper one for like $60

basically, without a multi-meter there is nothing left i can do to troubleshoot this amp?

 

[Kangaroux 5,000+ posts]

pretty much. you dont know if the amp is giving an output or not, without a way of measuring it's just guessing

 

[mikelaubach 10+ year member]

Well, if you are feeding it a signal (and you've already tried multiple source units), and you are getting no output, I cannot imagine a DVM/DMM showing anything on the output side. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif So something on the inside is bad. Unless you are missing something obvious, like:

Gain knob bumped and turned so far that you essentially turned off the amp.

Fuse blown somewhere that the power LED does not need, but the rest of the amp does.

Etc.

Still haven't mentioned what amp you have - what is the model number? There are more than one type of "1000W amp from Crunch." But at just over $100 (Amazon.com: Crunch PowerZone P1000.1 1000 Maxx Watt Power A/B Class Mono Amplifier: Electronics if this is the one), it might not be worth it to have it repaired. You'd have to make that call. Even buying a $60 DVM is going to cost you nearly half the cost of a direct amp replacement...

 

[Kangaroux 5,000+ posts]

Well, if you are feeding it a signal (and you've already tried multiple source units), and you are getting no output, I cannot imagine a DVM/DMM showing anything on the output side. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif So something on the inside is bad. Unless you are missing something obvious, like:
Gain knob bumped and turned so far that you essentially turned off the amp.

Fuse blown somewhere that the power LED does not need, but the rest of the amp does.

Etc.

Still haven't mentioned what amp you have - what is the model number? There are more than one type of "1000W amp from Crunch." But at just over $100 (Amazon.com: Crunch PowerZone P1000.1 1000 Maxx Watt Power A/B Class Mono Amplifier: Electronics if this is the one), it might not be worth it to have it repaired. You'd have to make that call. Even buying a $60 DVM is going to cost you nearly half the cost of a direct amp replacement...

an amp could be giving output but the sub could be blown. you make it sound like he doesn't need a DMM at all...which is completely false as everyone in caraudio should own a dmm..its the #1 thing for troubleshooting things like this

 

[mikelaubach 10+ year member]

an amp could be giving output but the sub could be blown. you make it sound like he doesn't need a DMM at all...which is completely false as everyone in caraudio should own a dmm..its the #1 thing for troubleshooting things like this

I'm not saying he doesn't need one. But I'm also not saying he does. There are shops out there (and plenty of them) that will do this sort of work for customers. How many noobs come on here all the time and have NO clue what they are doing, and are only making things worse. NOT everyone in car audio should have a DVM. There are plenty that should stick to a wallet and be done with it. I worked with a guy that was in that boat - he did not belong touching anything other than the volume and source knobs. NO CLUE what anything was, why it was there, or what it did. NOT saying the OP is in that state, but also unable to judge the OP other than that which he writes.

For the cost of the $60 DVM, OP can likely go to a shop and have them spend 15 minutes of time to diagnose the situation, and it better be less than $60 (figuring $100 shop rate). I am ALL FOR teaching a man to fish instead of giving him a fish, but not everyone has the ability, or interest, or time. The original post indicates that the OP is ready to just replace the amp, indicating that either he has no ability to further troubleshoot, or no time. Sometimes, we need to consider the audience when we speak or give advice...

 

[Ginkosu]

Is it possible that my subs are blown? I hardly ever pushed them, if that matters.

I'm all for DIY, I've done everything else so far, I just can't justify a $60 instrument right now when I can spend $100 and have the problem fixed, if that's the problem. I'll take the risk of not being 100% sure of what the problem is.

 

[pro-rabbit 5,000+ posts]

Does it power on? If so try to wire a different speaker to it and check for output. If it does nothing then try to use a different source for signal. Like using a mp3 player to give signal to your amp. Those would both rule out speaker failure and headunit outlying failure.

 

[mikelaubach 10+ year member]

And check with you friends, one of them, or one of their dad's (or possibly Mom's I guess) might have a voltmeter. Any other friends have amps that you can jumper to your sub to ensure the sub is not blown?

You also might be able to find a cheap $20 or less unit at Radio Shack, or Harbor Freight.