My Lowrance and Humminbird problem

Yesterday I went out on my boat and it was a hot day. I noticed that my Lowrance HDS 7 was hot and then it turned off and would not come on again. Later I was using my trollng motor and my Hummingbird Helix 7 got hot and it turned off and it would not come back on again. I thought it was a fuse but except both fish finders are not on the same battery. When I got home from the lake I connected both at different times. I was using my Power Converter and both fish finders were good. Then I went to my boat which is in storage. I connected both fish finders on the boat and they were ok. This has never happened to me. Does anybody know what I can do?

I am going to connect my Lowrance HDS 7 Live to a friend's boat that has another Lowrance fish finder. It might take awhile to ride around in the boat to see what happens. If nothing happens to my Lowrance, it has to be a problem in my boat itself. The Humminbird Helix 7 would be the same. I wish i had thought about it earlier but i am not very smart.

I looked at the specs and it says that they can operate up to 130 degrees. I know mines gotten so hot, that I couldn’t touch it, never had it turn off though. I can see it getting hot enough to turn off with the heat & humidity.