I build a small "shed" if you will for my generator and it stopped powering the power lasers around it.
I had two power lasers. Both on the ground. Then I build a one block height pad and a house around it. One side was open although this didn't seem to be the problem.
I moved a power laser on top of the building and it could no longer get power, after I had moved it, it was never powered again.
I tried moving the generator after this and the other power laser, but no matter what I did after that first power loss it was gone forever.