The approach I would use is this:
Explain to the student that his checkride is not that far off. He needs to perform the maneuvers to PTS standards. Start out with him chair flying them and talking them thru on the ground. By now he should know the procedures. Somewhere he should have the procedures written out so he should be able to regurgitate them. Query the student about why we do each maneuver (everything generally relates back to the traffic pattern and landing). Once he has shown he has an understanding of the why and can chair fly the how, go out into the plane and fly them. When he asks you a question, just politely explain that he needs to do it on his own to the best of his ability and you will brief him on the ground when you return. Remember to praise where it is do, not just focus on what needs help. Try to keep it balanced and possibly this student may need it even a little more off balance (more praise) to build their confidence up a little bit. It's okay to tell them "good job" in the plane when they do it right.
I have about 1,800 hours teaching and I have had my share of students like this. I find this method works well with most of them having this issue.
50 hours is towards the quick side of doing a private license so he must have the ability, it sounds like he is just lacking the confidence. Good luck!