Mate what is turning off?
The entire unit or just the sounder or GPS.
I sent my 178c away 1 1/2 months ago because of a problem with the sounder turning itself off.
Just got a brand new head unit back but its still happening so now I have sent the transducer back.If its not that then i guess it's the wiring or the 10 pin plug in the back.
Got sick of waiting so I've ordered a furuno sounder.
Scott