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Discussion Starter #1
Hi all
I was testing locations in my car, using an old speaker which seemed very quiet.
I turned the volume up and the amp went into protection.
The amp will not not come out of protection.
Is the output blown on the amp or something?
Please say this can be fixed, I’m very upset :(
 

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did you replace the fuses ( or confirm they are not blown) and disconnect all speakers and RCA's and just have power and ground connected? Then just touch a jumper wire from +12 to remote and see what happens.
 

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Hi all
I was testing locations in my car, using an old speaker which seemed very quiet.
I turned the volume up and the amp went into protection.
The amp will not not come out of protection.
Is the output blown on the amp or something?
Please say this can be fixed, I’m very upset :(
Check this video. May be of some help to you.


Sent from my ONEPLUS A3003 using Tapatalk
 

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did you replace the fuses ( or confirm they are not blown) and disconnect all speakers and RCA's and just have power and ground connected? Then just touch a jumper wire from +12 to remote and see what happens.
There are no fuses on the Zapco Z-AP series of amplifiers. And if the external fuse was blown, then the amp would not come on at all.
In the OP's case; the amp has gone into protection mode, and is stuck there.

But I would agree with miniSQ's suggestions (do the easy stuff first);
  1. Disconnect EVERYTHING from the amp, including the power and ground cables.
  2. Throw that old speaker in the garbage. It probably has a short in the winding, and caused a fault in your amp.
  3. Never test the amp with just one speaker... always use a pair. Always.
  4. Is the amp hot at all? If so, then give it time to cool down.
  5. Leave the amp alone for the rest of the day (it's going to be the longest day of your life). But let the capacitors fully drain, then hook power and everything back up.
It's a fairly robust amplifier, and the fact that it has gone into protection mode is somewhat encouraging (even though it's scary as shit right now). Best to just completely unhook everything from it, and leave it for a while. Give the internals some time to reset themselves...
 

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Discussion Starter #5
I have done as you both suggested and it still goes straight into protect mode, looks like I’ve blown something, I’m going to have to send it off for repair :( , this has really upset me today
 

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I guess when I said; "leave it for a while", I meant more than 10 minutes... I was thinking more like; the rest of the day.
You want to give the capacitors time to fully drain (can take up to 24 hours).

Just leave it for a while. At this point, you've got nothing to lose. It's Sunday...

Pull the back off the amp, and have a look inside. Anything obvious? (black/blown looking parts)
Does anything smell like burnt electronics? (it's a fairly distinct smell, and hard to miss)
 

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Discussion Starter #7
I left it for about 4 hours today, will it need longer ?
I did have a quick look inside, nothing smells or looks burnt.
It will be fixable though right ?
 

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Everything is fixable...
 

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Hi all
I was testing locations in my car, using an old speaker which seemed very quiet.
I turned the volume up and the amp went into protection.
The amp will not not come out of protection.
Is the output blown on the amp or something?
Please say this can be fixed, I’m very upset :(
A speaker that should have been playing at a reasonable volume sounded quiet. You turn up the volume and the amp goes into protection mode. This sounds like a bound and/or burnt voice coil.

Do you own a multi-meter?
  • First test. Lightly push on the speakers cone. Does it move freely or is there resistance when you push on the cone? Do you hear a scratching or scraping noise?
  • Next, check the DC resistance across the speakers terminals. What do you read? If you read something lower than an ohm the speaker is probably toast. You should read something close to the speakers printed rating +/- maybe 1 ohm.
  • Now, while holding the meter leads to the speaker terminals push on the cone and release. Does your DC resistance reading fluctuate? This is normal, the reading will vary as the voice coil travels through the magnetic field.
  • At any point while pushing on the speakers cone do you read near zero ohms? This could be where a damaged winding is hitting the motor structure and causing a short.
Another test. With the amp powered on and in protection mode:
  • Take your multi-meter and place it in DC voltage mode. Read the voltage across each channel.
  • You should read close to zero across each channel. Maybe a few hundred milli-volts at the most.
  • If any channel reads +/- a few volts or greater (like +/-30V) you have a blown channel.
There is also the possibility that there could be a power supply fault. But, I have no way to help you diagnose that without taking the amp apart.

After reading this thread and hearing your responses it does sound like the speaker was bad and may have damaged the amplifiers output. If the cone can't move freely then the speaker acts more like a dead short to the amp than an inductive load. I would expect the amp to be a little more robust than this. But, if it is older and has been in service for a while an output transistor may have given up the ghost.

I love ZAPCO. I use their amps myself. Unfortunately I can't stand the third party company in Chicago they used for repair work. At least this was the company they used 3 years ago. It took them 8 months after numerous phone calls, threats, and emails to get my amp back. Then when I did get it back they put a bad fan in it that made a howling sound. I had to pull it apart and replace the fan myself.

I hate to say this but unless your amp is still under warranty I would avoid using ZAPCO. Many local car audio shops offer amp repair services. I would suggest going that route first. From my experience this may save you months of frustration.

Ge0
 

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There lots of reputable third party repairs out there.

Amp repair is not rocket science. You just need to open the amp after the repair to make sure they used the right parts and solder is not done by a 5 year old.


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Any update from the OP on this?
 

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Discussion Starter #13
Hi there
I haven’t looked at it today
You think it’s worth plugging it in after leaving it 48 hours?
I was going to send it off tmrw to a repair shop
Cheers
 

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Can't hurt to power it up one more time...
The capcitors would have fully discharged by now, and there's a slight chance that the the amp has completely reset itself.
I have a hunch that you probably fried the OP transistors, due to a shorted voice coil in that test speaker you were using...
But you've got nothing to lose by powering it up, one last time.
 

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Discussion Starter #15
And are these easily fixable by a repair shop?
My question is, why can’t the amp shut itself down before causing itself damage, sounds poor to me
 

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It's a good design in the fact only a few parts may be fried and you didn't have a fire in your vehicle.
 

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It's a good design in the fact only a few parts may be fried and you didn't have a fire in your vehicle.
Good design and fire don't go well in the same sentence :)

Ge0
 
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