I have a Raymarine C80, when I turn it on all I see is a white screen sometime with some line running from top to bottom

SOURCE: Scanner not reponding - Checking HW

1.try with a new software 4.29
if you have an old one like 2.14 you have a problem.
2. After this try you C 80 on a nother boat or Raymarine dealer
than you will know if the C 80 works

SOURCE: GPS antenna

If your old antena is a Seatalk or NMEA antena you can use it for your C80
If you GPS antenna is older than five year change it.

SOURCE: I bought a C80 Raymarine

I would send your seatalk (Yellow and black) from your c80 to a junction box, send your rs125 to the junction box and another pig tail seatalk lead to the J-box coming from the autopilot. Now...on the raystar 125 connect the green wire to red, and the brown to black. Now connect the reds together, the shields and blacks together and finally the yellow's. The autohelm should power up the seatalk bus enough for your gps to work. the c80 offers power from seatlk but don't connect it's red wire.



Autohelm ---------------[ ]----------------GPS
|
C80---------------------------

Many times the shield is the silver wire we call it that since it has no other coating except its occasionally heat shrinked on the end.

RS125 -------Green------------------------0-------------RED------------ + power
--------RED------/

--------Yellow-----------------------0-------------Yellow---------- Data
--------Black------------------------0-------------Shield----------- -Power
--------Brown---/

SOURCE: RAYMARINE C80 SEATALK CABLE INSTALLATION

The Raymarine RS125 has five wires and can be either seatalk or nmea. It would be best to get a dealer involved. If things are hooked up wrong you'll fry your equipment.

SOURCE: c 80 screen has gone black,cant read infro, Bermuda

If you peer into the screen can you make out anything on it like as if the back lighting is bad? Also it may be set to night mode as well. You can try a factory reset. I have seen their screens go bad from time to time. If none of the above work. Send it in to Raymarine.