Lms 520c 5" Screen Color External Gps And 200 Khz Sonar System: I have a Lowrance LMS 520C on my boat. The GPS wi...

the light switch is in the power up button...turn the unit on let it boot up then push power button to set light as you want it do not hold down power button that will just turn unit off.. push the power button just one time if you want light brighter push till you get the back light you want

two things can be taking place 1 you have a bad key pad 2 you have a bad transducer(short in wire )

read the book that came with it you got to understand how it works and know how to set your unit before you can understand how it works and what you need to do to make it work and to get to what settings you want ..a fish finder is like a computer you got to program it to your likings .. I have a hd 10 structure scan on mine .. .now that's a nightmare to set but the book tells you everything you need to do and how to do it and how to get what your looking for and how to get to it

You can get the manual on the link below.

http://www.lowrance.com/upload/Lowrance/Documents/Manuals/LMS527-522_0152-181_120406.pdf

I'd suggest calling Lowrance.. Those guys are very helpful with step by step support... I just purchased a used boat with a 525c df on it and been troubleshooting some problems with it. Central time zone and best to call right when they open or turn on the phones at 8:15.

Quite often those transducers go out. Not 100% sure but would bet money on it. Call Lowrance customer support and see if the offer any more advised but more importantly see if they can replace your current one as a replacement instead of you having to pay full retail price. I purchased a new gps module through customer support and saved $150 off the normal retail price. Best time to call customer service is at 8:15am central time when the lines are turned on!

I have seen these listed on craigslist from 200 to 400 dollars. I do not know a store that carries them in stock other than the dealer may have it but you will pay threw the nose for it.

I have this problem as well! Mine is on the LMS 332C

If it is normal in deeper water, it is most likely just returning stuff in the water (debris, algae, anything floating around...choppy water can cause this). Try installing the latest updates from http://www.lowrance.com/en/Downloads/Product-Software-Updates/

If it doesn't help, adjusting the sensitivity or setting the SURFACE CLARITY option from the SONAR FEATURES menu to LOW, MEDIUM, or HIGH...whichever gives the best results.

I am having the same problem as joshuwan36 with my LMS 332C