jl audio 100/1

[mike49504]

When trying to power amp up i get nothing no lights no nothing.

when you remove just the battery positive wire the blue light will blink once then nothing try it again does the same thing.

wondering where i start

 

[Perry Babin]

Do you have the amp (1000/1?) apart so that you can remove the preamp board?

 

[mike49504]

yes amp is apart

 

[Perry Babin]

Remove the preamp board. Is there any green/gray corrosion near the power/ground terminal blocks?

If so, do NOT clean it yet.

 

[mike49504]

i dont see any but looks like a fresh solder job on the terminal blocks like someone messed with this already

 

[Perry Babin]

Was the board absolutely clean? Sometimes the corrosion simply looks like a light haze on the board.

Post the DC voltage for the terminals on the power supply driver board. Refer to the photo for the numbering of the pins. Place the black meter probe on the amplifier's ground terminal. Place the red meter probe on the point where you need to measure the voltage.

PS Driver board
Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:
Pin 9:
Pin 10:
Pin 11:
Pin 12:
Pin 13:
Pin 14:
Pin 15:

Also post the voltage on the 10 pin connector on the preamp board.

Preamp board
Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:
Pin 9:
Pin 10:

 

[mike49504]

Driver board

1=2.56
2=2.54
3=.02
4=.02
5=1.00
6=0
7=0
8=0
9=0.96
10=0.24
11=5.78
12=2.36
13=3.48
14=2.33
15=5.09

preamp board
1=0
2= -14.16
3=0
4=11.30
5=0
6=13.36
7=0.16
8=.07
9=13.18
10=.04

 

[mike49504]

also on the bottom of the board looks like a slight haze on power terminals

 

[Perry Babin]

Is the haze anything like what's shown in the attached image or does it look like flux?

 

[mike49504]

nope the one i have here is just flux residue

 

[Perry Babin]

OK. From what you've posted, it appears that both power supplies are operating and producing output. I need to check something when I get into the shop tomorrow.

 

[mike49504]

wondering what fets they are using for the power supply in this even no you said the power supplys are working looks like someone put new fets in this amp whats in it now are irf3707's

 

[Perry Babin]

I think the IRF3707s may have been the original parts.

 

[mike49504]

ok more checking into this amp 1 has been removed (irf3707) will the amp still power up if 1 is removed . Wondering if thats the problem or the problem is somewhere else since the amp wont operate normal

 

[mike49504]

Wondering if this amp will still power up with 1 fet removed (irf3707) so i can trouble shoot it before i order just 1 part

 

[Perry Babin]

Yes but you need to clamp the rest of them to the heatsink before you apply power.

 

[mike49504]

Wondering if you have any ideas on where to start looking?? Since you said the supplys are working

 

[Perry Babin]

I sent you a PM. I should have more information on this amp in about a week. Unless this amp has to be repaired as soon as possible. It would be better to wait.

 

[mike49504]

Ok Perry thank you ill wait on this one ill get somemore worked on getting alot of older fosgates later today

 

[mike49504]

Perry i did somemore testing on this amp. I found 1 transistor shorted the number on it are j111 and f0410ab wondering if i can sub something for this to do somemore testing