Raymarine ST70 losses saved settings

[Squanderbucks]

I have been using a Raymarine ST70 autopilot for several years all data connected thru the NMEA 0183 terminals of the Control Unit. And power to the unit came through the control unit which has it's own short Raymarine NG network. All was well and happy.

I Recently "upgraded" several other parts of my system,chartplotter, AIS, Radar etc and setup a NMEA 2000 network between everything. Needed to make a converter cable to tie the Raymarine NG backbone to the NMEA backbone as none is commercially available. All working fine. All devices see and talk to each other perfectly. Since only one power source can be used on an NMEA 2000 network there is a switch inside the ST70 Controller to flip off so the 2000 network will become the power source.

NMEA 2000 recommends an On/Off switch to the backbone when not in use to prevent power drain. Well the ST70 gets it's power from the backbone -
Now the ST70 autopilot brings me to the pilot setup screen where I must go through the steps to configure all of my preferences at each time.

With my old setup the short Raymarine NG network that supplied only the Autopilot was always on with only a breaker for that device. The on/off switch on the ST70 turned off the display but the power to the unit kept the memory alive. Only time I ever had to go through the preferences settings was when I turned off or replaced the batteries.

Is the ST70 supposed to have an internal battery to keep settings stored in memory when power is fully turned off? If so it may have failed as the unit is about 10 years old. If not any suggestions how I can prevent having to reprogram my preferences each startup.

[Squanderbucks]

I think I have arrived at a solution. Since the only device on the network that utilizes any power when turned off by its built in switch is the ST70 autopilot. All other devices totally power off with their On/Off button except the Actinsence AIS 0183 to 2000 converter which has no switch. I will just put a switch in the Actisence AIS converter's power wire to shut it off and leave the network powered up. That way the autopilot is ready to go when turned on with the power button and no settings will be lost.
Actinsence makes a couple of M/F wire ends that I can use to get into the cabling without having to cut into the network drop cable itself.

[pandw]

Hi Squanderbucks,

I have 2 ST70s, and one of them loses its settings as well, but often when actually powered up.

Did you ever find the cause and solution?

Cheers!

[Hirppa10]

Hello,

I just bought three ST70 displays from after market and two of the displays loses all settings when powered off.

Anyone found a solution or fix for this? Or any good quesses what component is broken? I even tried to open one but can't get the circuit board removed from the chassis.

It doesn't feel good idea to have n2k bus constantly powered.

[team karst]

Supercap, or Li coin cell are my first two guesses.