Raymarine Rl70C 'lost Radar / Sonar / Charplotter Fix' Alarms

[SpawnyWhippet]

I have the following devices interfaced using NMEA in my boat: Raymarine RL70C chartplotter / 24nm radar (display at chart table), L770D Fishfinder & DSM (display at helm), Raystar GPS, ST6001+ autopilot, ST60 Tridata.

Every few mins my Fishfinder multifunction display beeps several times and pops up with a 'lost radar/chartplotter' alarm and resets the range from 3nm to 72nm. I then have to zoom back down to 3nm.

Also, intermittently it will display an error saying 'lost sonar' or 'lost GPS fix' which requires me to reset the whole system in order to re-acquire a GPS fix.

I am planning some long passages and need to be able to rely on this gear - can anyone offer any solutions to check?

The local Raymarine dealer here in Singapore just said 'I don't know what the problem is' when I explained it, he just suggested to get his electrician out and check my power supply. However, his electrician installed my AIS and did an appalling job of the wiring, so I don't want him back on the boat.