Thanks for all the suggestions. I haven't had much time to work on it but I looked at the pins and connector again and everything looks brand new. It continues to not give any tones or display indications when first turned on after sitting or a day or 2 until I jiggle the coil cable. According to the previous owner he only used it a few hours and never in water. It looks basically new. He said it was his first detector so I am wondering if the issues I am experiencing caused him to sell it. I decided to call Garrett as suggested by Kac and they said it was never registered and it was 2-3 months past its warranty going by the date it was made. Garrett is sending me a slightly used replacement coil they said was used in some videos at no charge. Hopefully I will get it this coming week. I'll keep you posted.
Thanks again!