As the title says, I just picked up a sporty's SP-200 handheld aviation transceiver and I can't get it to function. I just replaced the batteries on it, and when I go to power it on, nothing happens. I have a working knowledge of electronic circuitry, and popped the radio open, but couldn't find anything obviously wrong with the device. If any of you have any experience with or have any idea what might be causing this, I'm all ears. Thanks for the help.