Me and a buddy went fishing Saturday in my boat. I have a couple month old 998. He has a year old 798. He brought his unit along with the memory cards. We put his memory card out of the 798 and put it in my 998. My unit would not read any of his coordinates. We then took screws holding the power cord on the 998 apart and hooked them to his 798. All coordinates were there on his unit. Just wondering why the coordinates wouldn't show up on my 998. Sorry for all the 98's. LOL