This link has all the Lowrance products and how to soft or hard reset them. Very useful tools when your unit is having minor glitches. Always verify your unit has the latest updates installed, then look up the reset options.
Lowrance Reset Keys (http://support.lowrance.com/system/selfservice.controller?CONFIGURATION=1001&PARTITION_ID=1&secureFlag=false&TIMEZONE_OFFSET=&CMD=VIEW_ARTICLE&ARTICLE_ID=2874)
Note: this list has all Lowrance products so you may have to scroll quite a bit to find yours