Close Call

I just finished modding the side of my case. It' s simple, just a hole for my 80mm intake. This is my first mod. Now, since last night (when I finished) I wanted to do more mods. So I decided to look at my front panel to see how easy it would be to put in Blue LEDs. It is really really easy. In the front (behind the bezel)the switches, speaker, and LEDs are all in a sort of plate and clip onto the metal part of the case. On the plate the 2 leds slide into a tiny box with connectors so there is no sottering needs to be done! Just pop the old LEDs out and slide in the new. Then I put it all back together.

HERE IS THE SHORTER VERSIONnot really)
When I boot up I smell something burning, so I quickly power off. I open up the case and the speaker wire is fried. Why did that happen. I only tinkered with the LEDs. So now I have the speaker and all of the wire wrapped in electrical tape and disconnected from the mobo. I would take it out, but all the mobo connectors are all in a bundle. I am just so glad that I did not fry my mobo. I dont know if that is possible but Im pretty sure that it is.
Also, where can I get Blue LEDs. Im thinking the Shack has them but havent been there in a while. Also how can I find out what Voltage my current LEDs are at, without buying a DMM. Unless DMMs are only a few bucks.
Heres what I did last night:

The Shack will have everything you need. The voltage is probably 5v, but it might not be. It would be best to check, probably with a DMM. They reage from cheap to really, really not cheap, so if you want one, you have a nice broad range. The shack will probably have some for as little as $5, but it'd probably be worth it to spring for a nicer model (say, $15 range). That way, you will know what voltage your LEDs run at and you will be able to do all sorts of other fun/bizzarre things to your computer in the future (may I suggest more fans and a bus). HTH