HELP! I think my jl amp is blown.

[Bumpin 86 Caddy]

I think my jl 500/1 v2 is blown. I blew a Cerwin Vega 15" stroker a few years ago and my friend tried to fix it. so to test it i hooked it to my jl 500/1 and now the amp doesnt work? power light is green but no power comes out. There is no fuse on the amp outside or inside that i could find. anyone know a simple fix perhaps? or a place i could send it cheap?

 

[nigelwright7557]

Its highly unlikely not to have a fuse somewhere or some form of protection.

 

[DREW028]

my 1000/1 went out bout a month a go. neighbor said he heard a loud thump come from my car in the middle of night???? Mines still come on also but no output. Im thinking something on the smaller preamp board went out. Havent had it check out yet but if i do it will be local. Price of repair would only be worth it if you could find someone local. After shipping back and forth repair and parts cost you be close to a decent used or maybe new amp with a few bucks more.

 

[DREW028]

i ended up getting a older autotek off ebay for $75 and it does 750watts rms. Decent for now

 

[Bumpin 86 Caddy]

I was using the amp to push my juggernaut 15" I need to upgrade anyway. But jl is supposed to be one of the best. It's only a year old. Does anyone know if there is a fuse on jl 500/1 amps?

 

[91h22a]

No fuse that I remember. I had one in for repair with similar symptoms, power light no output. It will likely need repair but it can be done. If you wanted to get rid of it someone like me would love to have it!

 

[Perry Babin]

With the black meter probe on the amp's main ground terminal, what is the DC voltage on each of the speaker terminals (amp on, no input)?

 

[Bumpin 86 Caddy]

Amp on. Black probe on amp ground. Meter set to 12v all speaker terminals 0.00

 

[Perry Babin]

It appears that the power supply FETs may be blown. Pull the bottom cover and look at the resistors in front of the transistors in the right-rear corner. They should look clean (second photo), not like the ones in the first photo. Look at all 8 of them.

 

[Bumpin 86 Caddy]

R600 to R607 they look more like the first picture. But not that bad. They look like the bands in the middle cracked they don't look burnt tho.

 

[Bumpin 86 Caddy]

And the transistors I suppose that's what they are. Look like they are supposed to be glued to the back. They are loose and not tight

 

[Bumpin 86 Caddy]

I am trying to get pictures on here my can't figure it out through my phone

 

[Bumpin 86 Caddy]

How could I find the value or power rating these resistor are? I can barely make out the color bands

 

[Perry Babin]

The resistors are 47 ohm 1/8w. The power supply transistors are shorted and will need to be replaced. The output transistors may also be shorted.

When you initially opened the amp, were the transistors clamped to the heatsink?

 

[Bumpin 86 Caddy]

I think they were. When I opened the amp there was a long metal piece with rubber clamping them down. Where are the power supply transistors and output transistors. What do they look like

 

[Perry Babin]

The power supply transistors are the ones adjacent to each of the burned resistors. The output transistors are the group of four transistors on the other end of the amp.

If you're going to do any more with this amp, please read the basic amp repair page (link in sig file below).

 

[Bumpin 86 Caddy]

Ok. Should the transistors. Be glued to the heatsink. Or just clamped and do you know the specific transistors I should get to replace them power supply say irf540 the others say irfz 44v

 

[Bumpin 86 Caddy]

Also, what do you think caused this to happen?

 

[Perry Babin]

Do you read 0 ohms between the legs of any individual IRF540?

 

[Bumpin 86 Caddy]

Set to ohm With both meters on any combination of the legs of the 540 ones it reads 0.L