In the first part, we investigate the singular BVP $${\frac{d}{dt}}^c{D}^{\alpha }u+{(a/t)}^c{D}^{\alpha }u=\mathscr{H}u$$ , u(0) = A, u(1) = B, c D α u(t)|t=0 = 0, where $$\mathscr{H}$$ is a continuous operator, α ∈ (0, 1) and a < 0. Here, c D denotes the Caputo fractional derivative. The existence result is proved by the Leray-Schauder nonlinear alternative. The second part establishes the relations between solutions of the sequence of problems $${\frac{d}{dt}}^c{D}^{{\alpha }_n}u+{(a/t)}^c{D}^{{\alpha }_n}u=f(t,u{,}^c{D}^{{\beta }_n}u)$$ , u(0) = A, u(1) = B, $${\left.{}^c{D}^{{\alpha }_n}u\left(t\right)\right|}_{t=0}=0$$ where a < 0, 0 < β n ≤ α n < 1, limn→∞ β n = 1, and solutions of u″+(a/t)u′ = f(t, u, u′) satisfying...