Hope its not to late, before you replace (buy a new one) call Lowrance. I have a 525 and working through some problems and they advised me that they would replace my unit for $200 no questions asked. To answer your question not 100% positive but I did see a recent question where Lowrance lost his unit and sent him the 525 as a replacement and the connections were different. I believe my 525 has a 5 pin system with one notch. Does yours have a external gps module? The 525 does!
Answers & Comments
Hope its not to late, before you replace (buy a new one) call Lowrance. I have a 525 and working through some problems and they advised me that they would replace my unit for $200 no questions asked. To answer your question not 100% positive but I did see a recent question where Lowrance lost his unit and sent him the 525 as a replacement and the connections were different. I believe my 525 has a 5 pin system with one notch. Does yours have a external gps module? The 525 does!