I didn't do that, voltage regulator was there in the correct place while the 9v was in place, and I didn't think that the 5v from the gameboy would kill it...but I do think it is strange that the gameboy won't power up with the power and ground connected

If you've ever accidentally connected the 9V to anything other than the input pin of the voltage regulator, you're toast.

Hello,

Recently built an arduinoboy using MEOW's kit (http://meowindustry.blogspot.com/p/products.html,) which relies on either the GB link cable or a 9v with a voltage regulator to power it. Long story short, it seems as though it was working (except for 2 LEDs being dead and possibly a problem with MIDI,) but I didn't have a link cable to test it out. Got a link cable, soldered the wires to the leads (including the gb 5v power) and the gameboy wouldn't turn on. I'm positive I soldered the correct pin from the 5v and ground to the arduinoboy, I took a look at it multiple times to be sure. So, gameboy wouldn't start, and arduinoboy wouldn't start. I put the 9v back in to see what the damage was, and the arduinoboy will not start anymore. Also noticed the voltage regulator gets extremely hot very fast now. So I know that's dead, but I also know that isn't needed if powering the arduinoboy via link cable. I guess my question is, is there any way to test my ATMEGA with a multimeter (I don't actually have an arduino, this kit only used the ATMEGA,) because I'm afraid I may have killed it.