I've got a Eagle 500c- everything has been working fine up until a few weeks ago. When I first turn on the unit, the bottom signal is strong, but the longer the unit is on the weaker the signal gets. It wont read the depth while moving and will barely show a thin line for the bottom- I'm thinking Ive damaged the transducer- any opinions?

what kinda transducer do you have? skimmer or thru hull.

thru hull on a 2005 triton tr-186- I installed it two years ago- sanded the spot and epoxyed in- worked fine until about 2 weeks ago and its getting worse- the deeper the water, the worse the return. I can turn off the unit for about 15 minutes, then turn it back on and its a little better for a little while then it plays out. Its a cheap graph to begin with and I've been thinking of upgrading. I just dont want to spend the $60 on the transducer and the time to install it and find out its the unit itself.

bump for help

Transducer going out or you have air bubbles in the epoxy all sudden. Thats your only 2 scenarios. Try calling lowrance for return, they have 3 year warranty. My suggestion-buy a humminbird and scrap the eagle.