Jl Audio 500/1v2 No audio.

[rhempz01]

4.986vdc

 

[Perry Babin]

Post the DC voltage on all pins of the LM393 just to the right of that resistor.

 

[rhempz01]

1) 4.96vdc
2) .002vdc
3) .094vdc
4) .000vdc
5) .092vdc
6) .196vdc
7) .44vdc
8) 11.44vdc

 

[Perry Babin]

Re-check the voltages. Confirm that pins 2 and 7 are directly connected. If so, re-post the voltage, double-check to confirm that all are the same through double-checking. Small differences are important.


Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:

 

[rhempz01]

Retested them all perry this is what i got. I really need to make a connector to remove the top pcb outof the way, when testing these amps.

Pin 1: 4.983vdc
Pin 2: .003vdc
Pin 3: .019
Pin 4: 0.00vdc
Pin 5: .092
Pin 6: .192
Pin 7: .812
Pin 8:11.56
______

 

[rhempz01]

ill be rechecking all of this after the ribbon cable and parts come in (Everything suggested in tutioral), its nearly inpossible to work on this like this.

 

[Perry Babin]

After assembling the cables, with an ohm meter, make sure that the pins that are supposed to be connected are connected. It's easy to get the connections backwards. If connected incorrectly, it could do a lot of damage.

 

[rhempz01]

Ok, I see how you marked them as a way to keep the in the correct oreintation. I ordered everything today. So I'll put these amplifier up for now until I get the cables to properly troubleshoot.

 

[rhempz01]

Ok so the cables came in perry and I got them all connected up correctly I believe.

 

[rhempz01]

This the best picture I could take of how I attached them.

 

[rhempz01]

I had to make some final adjustments, a fee cuts. But j ordered extra prices in case I break them. They do work. I wanted a clear picture for the forum.
393:
1.) 4.99vdc
2.) .002vdc
3.) .094vdc
4.) .000vdc
5.) .092vdc
6.) .196vdc
7.) .044vdc
8.) 11.44vdc

 

[Perry Babin]

Pull the orange 33uf cap near that IC to see if it's leaking.

 

[rhempz01]

It tests ok. I ordered a few 4r7 and the 33uf 16v caps. I didn't have any. The 4r7 in front of the driver card looked a little burnt, so I replaced it with a 5r1 I had from a Rockford. Same result. D611-d612 are reverse polarity diodes? When powered up a sizzling sound emmits from power supply transformer, or those diodes.

 

[Perry Babin]

D611 and D612 are for current sensing.

Did you power it up with the 33uf out?

 

[rhempz01]

Same result if the 33uf capacitor is out of curcuit.

 

[Perry Babin]

If you jump pin 5 to pin 8 will the low-voltage supply power up?

 

[rhempz01]

No.

 

[rhempz01]

The sound is from the power supply mosfets. The drive signal looks bad. Is that because of the low voltage supply is not functioning?

 

[rhempz01]

I went through the driver board and can't find any shorted components. And jumping the pin with or without the capacitor didn't power the low voltage supply up.

 

[Perry Babin]

To offer any suggestions on the drive, I'd need to see waveforms.

Did the voltage on pin 1 drop to 0v when you jumped 5-8?