Stupid DC jack screwed my circuit LED keeps burning out

[bhealy]

I built a Mini-booster and it worked great untill I pluged it in via DC jack. I built it as the schematic of GGG shows. I had the same problem with a Fuzz face. I think it's the DC jacks. Metal type that screw on from the outside. I bought them from  smallbear. Only now after I pluged in the DC wall wort it blew the LED. So I replaced the LED and now it just keeps burning out. I'm using a 8.2k resistor before the LED. I don't know what's goingon.

http://www.generalguitargadgets.com/diagrams/joam_lo_sm_amz.gif

[cd]

You've got a short somewhere.  Are you using a metal jack with a metal case (that is at ground), with an adapter that is outside ring positive?  That's a short.

[bhealy]

That sound about right. In the diagram it shows gound at the center pin of the DC jack. My box is metal and the box is ground so it makes sense it is shorting there. I guess I need to get those plastic DC jacks to make it happen.

[niftydog]

have you checked the voltage of the wall wart?

If the DC jack is shorting to the case, I doubt that would cause your LED to burn out.

Are you sure it's 8.2k and not 820ohms or something?

[Paul Marossy]

LEDs burn out when they get too much voltage. They can actually make an audible pop when they get too high of a voltage applied to them. (ask me how I know...). If your power supply was shorting out, you would get nothing - no power to burn up the LED.

[KORGULL]

I don't know what exactly is going on with your LED, but it might be a good idea to just get a 35 cent rubber grommet (probably 3/8 inside diameter) at the hardware store to put your metal jack in to isolate it from the enclosure if it is metal. If it doesn't solve the LED problem, it might still prevent a future problem.

[bhealy]

I put a new led in it and pulled out the DC jack from the box and rapped it in electrical tape temporarally. It work all day with a battery. I can't test it with a my wall-wort (Boss 9V) as I have to go to practice tonight and I just sold my tube screamer on ebay . Tomorrow I'm going to put a plastic piece in there and test it. I'll let you all know. Thank you!