Is my battery pack shorting out?

I have the Goal Zero Guide 10 Plus, and I think it is shorting out. I live in a humid climate (Singapore) and I this the humidity got to it. It is a camping tool so it should be able to withstand the humid climate of the jungle but I guess not. The battery pack looks like this:

So what happens is that occasionally when I go to charge my iPod, the lights on the battery pack will not turn on. I have to end up hitting it a few times to get it to work. Any ideas?