JL 1000/1 weird issue

mbates14

Member
2002-06-02 2:14 am
non
I have 2 of these here, and both do the same thing.

They work fine, but if you begin to give it any volume it starts cutting out, like its drawing ALOT of current.

Pulled the lids off, all the main input and output filters had bulging tops and split heatshrink labels. its been HOT.

So i recapped 1 of them so far, all new nichicon 3300uf 63v, and 2200 25v caps.

Powered the amp up, it still does the same thing. cuts out when you start to push it. Also after it plays for a bit, the main power supply filters are getting hot, along with the common mode choke attached to them.

Is this normal?
 

mbates14

Member
2002-06-02 2:14 am
non
Speakers attached, I have 11V from speaker terminal to chassis.

i have just a few millivolts between the 2 speaker connections.

Speakers disconnected, I get between 15 to 10v between speaker connections to ground. It will steady at 10v, but sometimes itll bounce around a little bit.

Between speaker connections, i get -2 to -9 millivolts and it bounces around alot.
 
Last edited:
I have 2 of these here, and both do the same thing.

They work fine, but if you begin to give it any volume it starts cutting out, like its drawing ALOT of current.

Pulled the lids off, all the main input and output filters had bulging tops and split heatshrink labels. its been HOT.

So i recapped 1 of them so far, all new nichicon 3300uf 63v, and 2200 25v caps.


With those caps the plastic top bulging is not really a good indicator that the cap is bad because it is more heat sensitive than the plastic sleeving wrapped around the cap and will distort & bulge at a lower temperture. Look underneath the plastic top, if the vents are not split the cap is most likely ok. Only way to know 100% a cap is ok is to check the cap out of circuit with a good cap meter that also has a ESR function.
 

mbates14

Member
2002-06-02 2:14 am
non
It seems ok. After the recap, its not cutting out and getting hot real quick. So i dunno. I sent it back with the dude, didnt hear back. Hes trying to run a 1ohm load on it and is having problems. Of course, they arnt 1 ohm stable.

But i do know this thing does pull an insane amount of current when you begin to crank it.
 
I got one, the reason the wrap shrinks and the top plastic lids bulge is because that transformer near them get extremely hot. I removed the lids and none of them had the metal casing bulge. I tested mine as far as i could with my power supply and got 45v prior to my ps cutting off. Jl should of used 105c caps near those transformers, mine have a 85c rating.
 

mbates14

Member
2002-06-02 2:14 am
non
well all these were buldged and starting to leak. Including, all the input caps too. I know all about the plastic caps popping up even though the cap is fine. I see that on every JL.

But no, Actually i need to take pictures to prove my point of what I have. Because, I have another one I gotta do with the same problem. The lables have split/shrunk on all the capacitors, and the top caps had fallen off because of this. And a few have popped tops.
 
If it happens to be just the caps, a few things that I can think of that could exacerbate the possible thermal issues. First off, are the old caps 85oC or 105oC, if 85oC rated that is likely a huge part of the problem. 85oC rated caps tend to be MUCH more sensitive to heat than the 105oC rated ones. Second, there is a good chance these caps are getting the heck thrashed out of them (they have to handle large currents AND the noise from the automotive charging system). It looks like the board uses SamYoung capacitors. A Korean company, unfortunately I have seen these fail in the past. I can't see what the models are for the caps. In image search I just saw an SHL (which are 85oC parts). I would recommend some better parts but without the model number I can't tell height of the caps.