I have this JL Audio 500/5 Rev 1 it plays on rear and sub. However it doesn't play on Front left or right. Moved selector switches and many combinations to no effect. All LED's on the boards are lit. I did clean all the switches before I got the rear and subs to play.
There are no shorted or open FET's. What am I missing?
There are no shorted or open FET's. What am I missing?
After I wrote this post, I don't know what happened. I turned the amp back on and now the "Low Ohm" light is lit and there is no LED's on any of the boards lit. What the h%$# did I do.
I did, I believe that I found the problem before I put it away for the night. There was a loose piece of solder between the rectifier middle and outer leg. Must have happened when I was removing old solder from 33 ohm resistor and resoldering it.
It then set there with power applied and not pulling in current at all... Then I had all my LED's back on and the rear and sub channels still working. Not the front though.
It then set there with power applied and not pulling in current at all... Then I had all my LED's back on and the rear and sub channels still working. Not the front though.
I don't know. Maybe someone else knows.
Are you getting signal to the muting transistors (or Cx13) for the front driver boards?
Are you getting signal to the muting transistors (or Cx13) for the front driver boards?
Just to clarify, Did you have 2 speakers on the dead channels and signal driving those channels while operating all switches in all combinations to see if ANY sound (music, static, noise) ever came from those 2 channels?
Didn't have music or static, I heard a click/pop when I moved the "Filter Mode" switch through a speaker. I didn't have 2 speakers hooked up at one time. I did it channel by channel.
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It's good that you found it. To have a bad solder connection on a double sided board on a component that is rigidly held into the board by its supports is very rare.
Well guess what, once I put the amp back together to truly test it. I noticed that with only power applied and no remote, I had a small current flow. When the amp was working and no remote, I had no current flow. So I applied remote, Low Impedance light comes on and no LED's lit up on any of the driver boards. Hence I am now back to square 1.
What causes the Low Impedance light to come on?
What causes the Low Impedance light to come on?
I think the LED may be triggered by multiple circuits in this amp. If I'm not mistaken, there are 3 main circuits (front/rear/sub).
Is it possible that you have a broken leg on one of the output FETs? A broken gate leg can cause intermittent problems like this.
Is it possible that you have a broken leg on one of the output FETs? A broken gate leg can cause intermittent problems like this.
I am pulling it apart now and looking.
You are correct, it does have a Front, Rear, and Sub
You are correct, it does have a Front, Rear, and Sub
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While the FETs are still clamped to the heatsink, see if you get a pulse of DC (measured directly across the speaker terminals).
On the sub speaker terminals, I am getting 56vdc on sub. on the Front I am getting 96mv and rear 71mv. As I was checking the voltages again, the amp started working and all voltages dropped, Subs to 14mv front 2.6mv and rear 12mv.
Start pushing on various components and various areas of the board with a non-conductive probe (dowel, bamboo skewer...). Can you find anything that causes the amp to malfunction when doing that?