the lack of
GPS is probably your
nmea 2000 network. that's where the gps will be. (19x?) there should be a fuse for it. you should be able to find a menu to list
nmea 2000 devices. see if anything shows up.
you might also have a
nmea 2000
depth / speed sender?... which would explain them both going down. though more likely you have a normal one.