jl 250/1 no output
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=116704
Printed Date: April 28, 2024 at 6:26 PM
Topic: jl 250/1 no output
Posted By: dyer
Subject: jl 250/1 no output
Date Posted: October 04, 2009 at 10:35 AM
I've been using a JL 250/1 amplifier for almost 3 years now. It has been working flawlessly.
All of a sudden, it has stopped.
I have double checked all wiring connections and have worked backwards confirming that the issue is with the amp, nothing else.
I've worked with these amps for years, and they have always seemed bullet proof to me.
Is there an internal fuse I don't know about, or anything like that?
Any help would be greatly appreciated.
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Dyer
Replies:
Posted By: i am an idiot
Date Posted: October 04, 2009 at 11:06 AM
There is no fuse inside the amp. My experience with the 250 is limited. However the 500/1 will light up with only remote and ground connected. So just because the amp is lit up, does not mean that it is getting power. You did not mention if the light was on or off, so since you did not say it was not lighting up, you could have a blown fuse at your battery. Use a volt meter to verify it is getting power. Connect the black meter lead to the ground terminal at the amp. Do not test it with black lead on the chassis of the car. Have you checked your speakers and wiring between the amp and the enclosure?
Posted By: dyer
Date Posted: October 04, 2009 at 12:23 PM
It is getting power. Fuse is fine. It is sharing the same distribution block as my amp for my mids/highs. This amp isn't having any issues.
I have also confirmed that power is present at both the +12V and the remote terminals with my multimeter.
Ground checks out fine as well.
I have double checked all speaker wiring.
The power light is on with a steady green led.
I have swapped every potentially bad component (speaker, wires, RCA cables, etc) with a good one to isolate the issue.
The amp seems normal is all cases, except there is no output.
I'm thinking the amp may have just finally "died", but I want to cover all my bases before tossing it in the trash.
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Dyer
Posted By: i am an idiot
Date Posted: October 04, 2009 at 1:07 PM
Remove the bottom cover, on the end of the amp nearest the speaker terminals, look for the Inductor(s). A large component with 2 or 4 wore connections to the circuit board. Check all 4 of the connections to make sure none of them are broken from the board. There will be either 2 identical ones with 2 legs each, or one larger one with 4 connections.
Also while in there, on the other end of the amp, look at the circuit board at the base of the power supply transistors. Look for dark spots. Do not try and remove the clamps from the transistors, you should be able to see if they are damaged just by the discoloration at the base of the transistors.
Posted By: dyer
Date Posted: October 04, 2009 at 1:46 PM
I've broken into the bare bones of the amplifier - colorful little suckers aren't they?
I gave the inductors a thorough look and they look as solid as the day they left the assembly line.
There are no dark spots or "burn" spots anywhere on either board.
So...back to the drawing board?
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Dyer
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