Thanks Longliner. I will buy another power cord and try it, but I've checked the cord I have and know that power is coming thru it (though I haven't checked the voltage). My 788 sit at the bow of my boat and is wired in to power exactly as the Ranger dealer installed the Lowrance unit that came on the boat. But....I did take the 788 and power cord and wire it directly to a new battery and still it did not work. It must be the unit somehow. I'd love to talk with a tech person at Humminbird, but so far have not been able to get in touch with one. I've called a dozen times and each time I've been put on hold. Once I held for nearly an hour and other times for 30 to 45 mins. Only yesterday when I called again did I finally get to talk with a real live person and he was not a tech person (or at least he never gave me a chance to tell him what was wrong with the unit.) I've heard good things about Humminbird, and am really trying to give them a chance. I've had four Lowrance units previous to this and never had but one to give me the slightest glitch....and when that happened Lowrance took care of it in good order. I have a new 998 SI Humminbird on the dash of my boat.....but it may soon be up for sale if I can't get this 788 working.