JL audio E1400D

mike49504 · 24th June 2010, 05:43 AM

I recieved this amp in for repair and the outputs where shorted i replaced all of then Irf540's I put new Irf540N's back in it. I also replaced the 47 and 10 ohm resistors.

Amp powers up But its not producing NEG rail voltage .

Any thoughts on what to check?

Perry Babin · 24th June 2010, 05:48 AM

Most of the JL class D amps have no negative rail voltage.

mike49504 · 24th June 2010, 05:50 AM

So on the Irf540's 2 of them have 70 volts on the middle legs the other 2 no voltage present on them. Is that normal or is there a problem somewhere?

Perry Babin · 24th June 2010, 05:53 AM

One group of parallel outputs should have rail on the center leg. The other group of parallel outputs should have their 3rd leg connected to ground. The 3rd leg of the first group and the center leg of the second group should be at 1/2 of rail.

mike49504 · 24th June 2010, 06:01 AM

Ok with black probe on ground terminal 1 group of outputs 70 volts of rail on middle legs.

Next group of outputs red probe on B+ terminal i have 13.8 volts on 3rd legs

What do i need to check next since i have no output ?

Also dont know if this helps or not but only have the green LED's are lit on the board

Perry Babin · 24th June 2010, 07:42 AM

Do you have 0v DC on all of the speaker terminals (black probe on ground terminal)?

Is the protect LED lit?

mike49504 · 24th June 2010, 02:02 PM

No Dc on any output terminals. Proctection light is not lit.

I noticed the regulators 317 and 337 are getting hot very quicly though

Perry Babin · 24th June 2010, 02:17 PM

Do you see a square wave on any pin of either of the ICs marked HC132 on the driver board?

mike49504 · 24th June 2010, 02:32 PM

any other way to check it? I need a new scope mine was sitting on the shelf and came crashing down and hit the floor now it doesnt work right

Perry Babin · 24th June 2010, 02:34 PM

I don't know enough about this amp to check it any other way.

24th June 2010, 05:43 AM	#1
mike49504 diyAudio Member Join Date: Sep 2006	JL audio E1400D I recieved this amp in for repair and the outputs where shorted i replaced all of then Irf540's I put new Irf540N's back in it. I also replaced the 47 and 10 ohm resistors. Amp powers up But its not producing NEG rail voltage . Any thoughts on what to check?

24th June 2010, 05:48 AM	#2
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	Most of the JL class D amps have no negative rail voltage. __________________ Links >> Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing --- Basic Switching Power Supply Design --- Basic Computer Skills << Links

24th June 2010, 05:53 AM	#4
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	One group of parallel outputs should have rail on the center leg. The other group of parallel outputs should have their 3rd leg connected to ground. The 3rd leg of the first group and the center leg of the second group should be at 1/2 of rail. __________________ Links >> Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing --- Basic Switching Power Supply Design --- Basic Computer Skills << Links

24th June 2010, 07:42 AM	#6
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	Do you have 0v DC on all of the speaker terminals (black probe on ground terminal)? Is the protect LED lit? __________________ Links >> Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing --- Basic Switching Power Supply Design --- Basic Computer Skills << Links

24th June 2010, 02:17 PM	#8
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	Do you see a square wave on any pin of either of the ICs marked HC132 on the driver board? __________________ Links >> Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing --- Basic Switching Power Supply Design --- Basic Computer Skills << Links


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

24th June 2010, 05:50 AM	#3
mike49504 diyAudio Member Join Date: Sep 2006	So on the Irf540's 2 of them have 70 volts on the middle legs the other 2 no voltage present on them. Is that normal or is there a problem somewhere?

24th June 2010, 06:01 AM	#5
mike49504 diyAudio Member Join Date: Sep 2006	Ok with black probe on ground terminal 1 group of outputs 70 volts of rail on middle legs. Next group of outputs red probe on B+ terminal i have 13.8 volts on 3rd legs What do i need to check next since i have no output ? Also dont know if this helps or not but only have the green LED's are lit on the board

24th June 2010, 02:02 PM	#7
mike49504 diyAudio Member Join Date: Sep 2006	No Dc on any output terminals. Proctection light is not lit. I noticed the regulators 317 and 337 are getting hot very quicly though

24th June 2010, 02:32 PM	#9
mike49504 diyAudio Member Join Date: Sep 2006	any other way to check it? I need a new scope mine was sitting on the shelf and came crashing down and hit the floor now it doesnt work right

24th June 2010, 02:34 PM	#10
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	I don't know enough about this amp to check it any other way. __________________ Links >> Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing --- Basic Switching Power Supply Design --- Basic Computer Skills << Links

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
jl audio 500/1	megael9	Car Audio	12	28th May 2010 11:01 PM
Jl audio 1000/1	mike49504	Car Audio	1	22nd May 2010 08:21 PM
jl audio	nicandjade	Swap Meet	0	2nd September 2006 10:35 AM
JL Audio vs Polk Audio	xfsrg	Car Audio	2	17th October 2004 06:09 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read