I need help diagnosing my JL 500/1 series amp The power light comes on and whatnot but seemingly no sound comes from it. I was hooked up to a brand new speaker and head unit with no success, I tried a friends system with same results. It must be the amp...but what inside the amp specificily I'm not sure of??? Any help diagnosing this little beauty would be appreciated especially since I have 2 of these amp's.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
burned spots??? seems burned under the allen wrench kinda gray smokey
You'll have to post higher resolution images for them to be of any use.
Does this one read 40v on the positive and negative speaker terminals?
Does this one read 40v on the positive and negative speaker terminals?
Update: a college professor of mine tried to help me diagnose this amp and told me that: Q505 Q600 Q601 Q602 Q603 Q604 were all bad and needed to be replaced. I believe he wad baseing this on a resistance check from the back side of the board??? Does this make sense to you? I'll see what I can do about better pictures would you like me to re upload them?
If that's true, Q504, 505, and 600-607 will have to be replaced. Do you read something near 0 ohms between legs 1 and 2 of any of the transistors above?
ok got em off so. I'm also noticing r600-r607 all look burnt up too. And maybe even Q 608 and Q611 like a little like solder started to melt away. Try this picture thing again.
An externally hosted image should be here but it was not working when we last tested it.
Last edited:
All of those will have to be replaced also. They're 47 ohms. The size is 1206.
It appears that the PNP drivers have also overheated. You may need to replace those. You'll need to check the drive signal after you remove the FETs.
It appears that the PNP drivers have also overheated. You may need to replace those. You'll need to check the drive signal after you remove the FETs.
Without a scope, you have to use the DC voltage on the driver transistors. With no power supply FETs in the board, you should read approximately 5v on the 3rd leg of the 4 driver transistors (Q608-611).
Perry I wish you taught my advanced electrical class next semester, I've already had one advanced automtive electrical diagnoses class, but they didn't even scratch the surface for stuff like this!!! Just wanted to say thanks for the help in advance
I'm Planning on this to college so my professor can veryify my work for me anything else that I should check while I'm there? Plus I might have access to an scope there as well.
You need to check all resistors and transistors that were driving any power transistors (FETs) that failed.
can you give me a value for the three legs outs of the bord for bothe the ifrz44n's and irf540's ?and also the way to test them I removed them all from the board but I'd just like to know whats good and bad know that their out.
can you give me a value for the three legs outs of the bord for bothe the ifrz44n's and irf540's ?and also the way to test them I removed them all from the board but I'd just like to know whats good and bad know that their out.
- Status
- Not open for further replies.