First of all this is not a paradox, unless you’re not explaining something, there are two yous past and future, if past self turns off the machine before seeing the numbers nothing happened, if he turns it off afterwards the information has already been transferred so nothing happens either.

I have a feeling you might have recently watched Primer and are thinking of a similar working tome machine, where the machine needs to be powered on from past until future. But if this situation happened in Primer it wouldn’t be a problem either because you’re not in the box after you leave it. It’s a bit weird, but if you imagine time as horizontal lines, the box allows you to travel diagonally, so you only exist inside the box in that timeline at the moment of exiting, before that you were in a different timeline, so if you exit the box, wait a while and turn it off you’re only preventing yourself from using the box again. In fact that’s one of the big reveals of the movie, except it’s said in passing by mentioning that the boxes are multi-use.