Balls go on hunger strikes, it happens, especially during winter. A lot of the time there is no reason. Balls are just finicky sometimes and enjoy keeping us on our toes.

As far as weight, pics would help, but now that you have a scale, monitor his weight. If he starts losing drastic amounts of weight, then I would be concerned.

What are your temps? Humidity? Hides? Location in the house? Handling practices? Describe your whole setup in as much detail as possible, pics will helps too.

Since it had been a while since he last ate, when he does eat again, make sure it is a little smaller meal. Do this for a couple meals so it gives his body a chance to build back up to eating normal sized meals. You might also give mice a try. Those that read my posts know I am very against regular feeding of mice, but sometimes it helps get them started back on feed. Another option would be African soft furred rats if you can find them in your area. These are like candy to a ball python and have helped a LOT of people get picky eaters back on feed.