I had a JL Audio GMAX 1200 monoblock amplifier repaired by JL Audio on July 17th 2015, and yesterday August 31st the power cut out 10 minutes into my morning commute, ~15 days after the 30-day warranty was up. I'd rather not dish out another $250 for a repair, does anyone have a schematic or can recommend some components to check? I have a bachelors in computer engineering tech and masters in CS and access to a bench at work so I know my way around hardware.
And for the question on everyone's minds, what the **** am I doing to burn out an amplifier twice in 3 months. I have 10AWG oxygen free copper power and ground wires, grounded to the huge rear passenger seatbelt bolt with the finish scraped off of the frame of the car for the most surface area contact. In addition to the original post screws I secure each wire to the amplifier with electrical tape. I am running a JVC stereo with 2.5V subwoofer preamp output with subwoofer output level at 6 out of 8 and the main volume at 20 out of 40, with the JL GMAX at the low voltage input switch which is 200mV to 2.0V, and about 3/4 input sensitivity on the amp, no bass boost. Only questionable thing is I am storing the amp underneath the rear passenger seat between the cushion and the frame to avert theft after my last amplifier got stolen out of my car. JL GMAX is class D and is supposed to have thermal protection where it lowers the output above safe operating temperatures.
I did check the fuse and its not blown.
Any help and advice is appreciated. Thanks.
And for the question on everyone's minds, what the **** am I doing to burn out an amplifier twice in 3 months. I have 10AWG oxygen free copper power and ground wires, grounded to the huge rear passenger seatbelt bolt with the finish scraped off of the frame of the car for the most surface area contact. In addition to the original post screws I secure each wire to the amplifier with electrical tape. I am running a JVC stereo with 2.5V subwoofer preamp output with subwoofer output level at 6 out of 8 and the main volume at 20 out of 40, with the JL GMAX at the low voltage input switch which is 200mV to 2.0V, and about 3/4 input sensitivity on the amp, no bass boost. Only questionable thing is I am storing the amp underneath the rear passenger seat between the cushion and the frame to avert theft after my last amplifier got stolen out of my car. JL GMAX is class D and is supposed to have thermal protection where it lowers the output above safe operating temperatures.
I did check the fuse and its not blown.
Any help and advice is appreciated. Thanks.
Did you pull the cover to see if you cold see anything obvious?
Did you put a voltmeter on the terminals of the amp to confirm that you had a good ground, B+ and remote supply?
Did you put a voltmeter on the terminals of the amp to confirm that you had a good ground, B+ and remote supply?
If it is a 1200 watt mono block amplifier I certainly would not be running 10 awg. wire to it. That seems a bit small from my experience.
A basic Scosche 1200 watt amp kit found in wal-mart will have 4 awg.
A basic Scosche 1200 watt amp kit found in wal-mart will have 4 awg.
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Sorry, its a 4AWG wiring kit, not 10.
I took the amp into the lab at work and it powered right up. I checked the voltages and continuities in my car and they were all fine. Reconnected the amp and it powered up. No idea what happened. The end of the remote wire must've wiggled away from the contact inside the remote terminal. I stuffed it in and screwed it down tight this time.
Thanks for your time and responses guys. Sorry for the false positive. Another case of "did you turn it off and turn it back on again."
I took the amp into the lab at work and it powered right up. I checked the voltages and continuities in my car and they were all fine. Reconnected the amp and it powered up. No idea what happened. The end of the remote wire must've wiggled away from the contact inside the remote terminal. I stuffed it in and screwed it down tight this time.
Thanks for your time and responses guys. Sorry for the false positive. Another case of "did you turn it off and turn it back on again."
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