I bought a 7.3 about a year ago and the previous owner gave me a superchip cortex with it brand new in the box never used. A couple months ago i plugged it in and tuned it to the millage save setting. Today i wanted to erase the tune and when i plugges the tunner into my truck and the tuner wouldnt turn on. Ive tried it multiple times with the same result. So im just wondering what could be wrong. Any help would be appreciated. Thanks.