Thats why I built Preneur; a platform where entrepreneurs can find interesting problems to solve. Preneur aims to concentrate the precious time of entrepreneurs towards solving problems rather than searching for problems to solve.
Preneur is launching on the 25th October. You can join the waiting list to get notified of when we launch.
On HN there's a question every other week, usually very few answers or unanswered. For example "Ask HN: What are problems HN users would like to solve" https://news.ycombinator.com/item?id=33893427