Out of all may hunting equipment, the least reliable is the trail cameras!! I have one old moultrie flash thats still working well. The new m-80 moultrie I had to return. Customer service was a joke! The worst camera I've owned is a Cuddyback with the worst customer service. They actually told me I probably shouldn't be a cuddyback owner. So I took their advise. The cuddyback I did own was stolen. That was a blessing, now they have to deal with it.
Mrbb we are both old enough to remember when you payed good money for a product it would perform, last a reasonable time, and you could get it fixed locally. If a trail cameral company did that, they would corner the market! I've ranted enough, back to your question/problem.
I was thinking that the only thing that could make them all go bad at once would be a lighting strike. Just a thougth.