I have 2 LCX 15 MT GPS Units on my boat and the unit on the console will tell you when turned it on that the program is corrupt and to contact your provider. I did contact the provider twice and about all I got from the support department at lowrance was that parts were hard to come by for this unit. The problem with the unit is that if you turn the unit off there is a flicker on the screen and then it turns off and if the unit is turn back on for an hour or so with the corrupt sign left on/unit turned off and back on the unit will usually come on correctly.
649J

GPS - Lowrance - LCX-15MT GPS Receiver