We consider the partial theta function $\theta (q,z):=\sum
_{j=0}^{\infty}q^{j(j+1)/2}z^j,wherez\in Cisavariableandq\in C,0<|q|<1,isaparameter.SetD(a):={ q\in C,0<|q|\leq a,\arg (q)\in [\pi /2,3\pi /2]}.Weshowthatfork\in
Nandq\in D(0.55),thereexistsexactlyonezeroof\theta (q,.)(whichisasimpleone)intheopenannulus|q|^{-k+1/2}<z<|q|^{-k-1/2}(ifk\geq 2)orinthepunctureddisk0<z<|q|^{-3/2}(ifk=1).Fork=1,4,5,6,\ldots,thisholdstrueforq\in D(0.6)$ as well.