Amp wont power on, just keeps blinking, help!

[Mach1Chris]

Hey everyone,

I bought a used Clarion APX400.4 amplifier off a friend. I wired it up and when I try to power it up (turn on the stereo), the power LED just keeps blinking once every maybe 5 seconds and I hear a slight pop in the speakers. I tested the connections with a multimeter and they all appear fine. Any ideas what might be wrong and/or how I can fix it?

Thanks,
Chris

 

[Stocker]

open the case. look for anything that looks or smells burnt.

 

[sdoom]

There is a short in the speaker wiring or the speakers itself. If you disconnect the speaker harness and the amplifier still behaves like you said, the amplifier is damaged.

If so, I assume a short in one (ore more) output transistors. That will always activate the protection curcuit. Some amplifiers will not turn on at all if in protect-mode. Some amplifiers will try to turn again after a certain period of time (usually around 3-5 sec). You amp is like that.

So what happens is : the amplifier is turned on --> the protection curcuit detects the short and powers off --> 5sec delay time passed -->amplifier turns on -->the protection curcuit detects the short ......

You can find the faulty transistor with a diode-tester or ohm-meter. if you are not confident in electronics bring it to a repair shop.

 

[martin88]

I have that problem with my jvc amp and i unpluged it left it for a bit and it worked also using the remote helps. I ghet the problem now every few months

 

[sdoom]

how old is that JVC - a,plifier ?


I assume that´s a bad solder joint inside your amplifier. The quality of how those units are assembled is very low, even in the higher-price range. It´s tough business an they want to make big money 🙂

If you are confident with a solder-iron or know somebody who is then take the amplifier apart and re-solder all joints on the curcuit board, that will probably fix your problem.

But also make sure that your speakers are in fine condition. Connect an ohm-meter to each speaker and gently/slwoly move the membrane of the speaker in both directions . If your ohm-meter shows a frequent short then you have a bad speaker.

 

[martin88]

cheers ill try it could it have been that the jvc amp has been shorted in the past because it wasnt new when i got it and the falt only happens when dissuesed for a wile normaly when i go on holiday is that still gona be the problem

 

[stone885]

OK... so i am kinda new to the car audio thing... i just purchaced a box with 2 12's prewired (works) and a pioneer 760W amp (reccomended at the store for the speakers) and all the needed wiring.


i have hooked everything up as per instructions and the amp wont power on......

i am also using a converter from the rear speaker wires to rca to the amp.



pleeease help

 

[ChevS-10]

If your amp has High inputs, don't bother with the converter and just connect the speaker wires with the high inputs.