my garmin gps 320 isnt working properly help

[dawgmode]

Wassup guys,
I have a Garmin gps 320 and its been working fine the las 9 yrs its been on the boat but last week i turned it on and it picked up signal in a few seconds and then about 15minutes later it lost all signal until about 6hrs into fishing, it picked up signal again. So i cleaned the antenna connection in the back of the unit. Then a few days later i was making a trip over to Andros for the evening and it wouldnt pick up signal at all when i turned it on until like a half hour into the trip it picked up signal and on the way back from Andros it didnt work at all. What do you think is the problem

[Skinny Dip]

My 178C did something similar. It sat inside for a few months and when I put it back into the boat it took about an hour to acquire satellites. It did this a few times but then started to work normal. Then about a month later it just crapped out all together. Its on its way to garmin right now.