Rl70c raymarine depth finder problem

If you are having trouble loading charts on your Raymarine E80 chartplotter, there are several things you can try to troubleshoot the issue:
1. Check the chart card: Make sure that the chart card is inserted correctly and that it is compatible with your chartplotter. Some chartplotters require specific types of chart cards, so check the user manual or contact the manufacturer to ensure compatibility.
2. Check for software updates: Make sure that your chartplotter has the latest software updates installed. You can check for updates on the Raymarine website or by contacting customer support.
3. Check the chart source: Make sure that the chart source is set correctly on your chartplotter. If you have multiple chart sources (e.g. internal memory, external card), make sure that the correct source is selected.
4. Check the chart format: Make sure that the chart format is compatible with your chartplotter. Some chartplotters only support certain chart formats, so check the user manual or contact the manufacturer for compatibility information.
5. Check for obstructions: Make sure that there are no obstructions blocking the GPS antenna or interfering with the chartplotter's reception. Obstructions can include tall buildings, trees, and other objects that block the line of sight to the GPS satellites.
6. Reset the chartplotter: Try resetting the chartplotter to its default settings. This can sometimes clear up software glitches or other issues that may be preventing the charts from loading.
If none of these solutions work, you may need to contact Raymarine customer support for further assistance or repair.

Take care and have a great day! -Alex

either the cord to the chart plotter is faulty or the chart plotter itself is dead short
have an electrician do an insulation test and circuit test on the cord and plotter unit

Sounds like you do not have your transducer connected.
You will know it is working if you have a bottom sounding. If you have a bottom sounding (depth reading) and it is correct then you may have to fine tune the finder to see the fish.
I have the same finder on my boat. http://njsaltfish.com/index.php/captainsfocus?sid=61

Likely your DSM25 (that little box that connects the transducer to the display) will need to be rebuilt. The red LED is saying that there is an internal fault with the unit. You would need to send the unit in for repair through Raymarine (as there really is not anyone else who can do it), and they would have to replace the main circuit card in the box. I believe that they are charging either $150 or $175 to repair those now... but likely the only way you will get that one to work again.

http://www.fixya.com/support/r3771170-phone_water_damage

If both plotter works but they have no comunikation
RESET the RL 70 AND L760
This is how it works
press the powerbutton when you have picture press the menu bottom
than systemsetup and than four seconds the menu bottom.
Do this on both plotter normaly after this it works again

I think you use the NMEA output to the autopilot .
The plotter shows you only when you have a seatalkconection with a Raymarine autopilot on you Plotter

sounds like it died...i happen to have one for sail with 4k dome

I have one of these same units brand new for sale real cheap

I did exactly what you wish to do a couple of years ago. It was a 5 minute job, cut out the same except the new unit needs a little more space behind and it was a plug for plug swap. Works great and swaps data between the matching chart plotter to give chart overlay on the radar
Richard