I have a jl 300/4 here with one channel out. i replaced the outputs and one bad 10 ohm resistor on the driver board. there is a smt zener diode that is shorted that i need to replace on the driver board. i need the value of it or an acceptable replacement part number or marking value. the diode looks like it says 6.8Y on it. this diode is mentioned in Perry's tutorial but the value was not given.
Thanks in advance.
Thanks in advance.
The 5.6 may work well enough to allow you to get it up and running but I'd recommend ordering the correct parts before you put it back into service.
If the amp doesn't work properly with the 5.6, order and install the 6.8 before you do anything else. If it works well with the 5.6, you can be relatively sure that there are no more defective components.
If the amp doesn't work properly with the 5.6, order and install the 6.8 before you do anything else. If it works well with the 5.6, you can be relatively sure that there are no more defective components.
same side (rear) but i think it is the other channel. and i get no sound out of the channel that i put the zener in but no dc offset.
i may just give this one back to the owner because i have spent too long on it unless there is a reletively simple solution.
i'm getting about 2.5 amps of idle current without a limiting resistor and no protection lights.
i may just give this one back to the owner because i have spent too long on it unless there is a reletively simple solution.
i'm getting about 2.5 amps of idle current without a limiting resistor and no protection lights.
Do you have any open resistors near the output transistors you replaced?
You need to use your meter to determine if the channel with DC is the same as the one with the shorted Zener. Measure the resistance from the gates of the channel with DC to the driver board pins. There are resistors in series so it's better to go from the driver board side of the gate resistor. From there to the driver board, you should read 0 ohms.
Can you confirm that you have signal at the input of the driver board for the defective channels? I don't know which pins are audio input. You may have to check the working channels to determine which are the input pins.
If you have one or more pairs of output transistors getting hot, the bias may be set a bit too high.
You need to use your meter to determine if the channel with DC is the same as the one with the shorted Zener. Measure the resistance from the gates of the channel with DC to the driver board pins. There are resistors in series so it's better to go from the driver board side of the gate resistor. From there to the driver board, you should read 0 ohms.
Can you confirm that you have signal at the input of the driver board for the defective channels? I don't know which pins are audio input. You may have to check the working channels to determine which are the input pins.
If you have one or more pairs of output transistors getting hot, the bias may be set a bit too high.
Yeah they have flat rate repair but its ONLY through there product dealer network. Flat rates that I am aware of are minus the 30 to 40% dealer knock up that there dealer typically puts on top of there factory flat rates.
In your case I believe its $90.00 and you will most probably get a B stock unit returned in a new box, so it appears to have been replaced with a new amp. Pretty good turn around also , if you can get one of there dealers to cut his margins they put on top of JL's factory flat rate, you would be getting a deal and a half... Good luck on your repair....
In your case I believe its $90.00 and you will most probably get a B stock unit returned in a new box, so it appears to have been replaced with a new amp. Pretty good turn around also , if you can get one of there dealers to cut his margins they put on top of JL's factory flat rate, you would be getting a deal and a half... Good luck on your repair....
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