I have a Lowrance Elite 7 Hdi which is about 18 months old. It stopped booting up properly and the right and down arrow buttons were not working properly. I contacted Navico and was informed that that they no longer repaired the units once out of warranty but if I would like to send them $574 they would send me a refurbished one. This really P'd me of as I dabble with computers and mobile phones and it seemed ridiculous that some thing as simple as this could not be sorted for a $100 or so. Anyway I decided to have a go myself, the booting issue was solved by a hard reset I then did a firmware update and everything was ok again. This left the buttons to fix, I removed the back of the unit and removed the motherboard to find a bit of corrosion under where the buttons pressed on the board, sprayed on a bit of contact cleaner and removed the corrosion. Put it all back together again plugged it in and away it went. The whole process took around an hour. So for $36 for a set of torx screwdrivers and a tin of contact cleaner I saved myself $540. I took a few pictures and anyone who needs to pull a Lowrance apart let me know