Ethernet shield fail after a month

Hi,

I have setup and run arduino and ethernet shiled for a month 24-7(never off). But then it went out, LAN light were off(malfunction) in ethernet shield and it get very hot in short time. Everything is fine, modem still work, sensor still work and etc. So what could be the reason?

Thanks

Can be moisture, bad soldering, bad luck, peak voltage on the ethernet, anything.

Tell us more about where the shield stands/hangs /whatever to get an idea. Maybe post a picture?

I place it at the wall inside a small house, it has plastic enclosure and steel enclosure to protect it. The house is beside a river. I am using it to transmit arduino Uno rivel level data through the internet using 3g modem. The last data did show a sudden increase of river level of 0.1 meter, this might mean it is raining heavily outside. Might be moisture, if that is the case how to protect it?

My power power adapter is 5V - 250A can this be the reason?

Thanks