Monodromy of the generalized hypergeometric equation in the Frobenius basis

We consider monodromy groups of the generalized hypergeometric equation [z(θ−α1)⋯(θ−αn)−(θ+β1−1)⋯(θ+βn−1)]f(z)=0,where  θ=zd/dz, in a suitable basis, closely related to the Frobenius basis. We pay particular attention to the maximally unipotent case, where β1=⋯=βn=1β1=⋯=βn=1, and present a theorem that enables us to determine the form of the corresponding monodromy matrices in the case where (X−e−2πiα1)⋯(X−e−2πiαn)(X−e−2πiα1)⋯(X−e−2πiαn) is a product of cyclotomic polynomials.