I'm assuming he went dead.Sorry the real hint is:
@Pi
Your clue has me going in the wrong direction: trying to find some way the 4 numbers in a row are related with those 4 symbols. Ie 7+5=12, 7-5=3, 7×5=35(but it's 2), and 7/5 rounds to 1.
Spoiler for Hidden:
I just didn't want the hint to give it away too easily.