This thread is a few months old now, but since I had the identical problem with a ql17 I bought at a thrift shop this morning, I though I would share my experience.
In manual mode, I think the expected behavior of the ql17 is that the aperture blades will snap into the desired position when the rewind lever is pulled. Mine, however, were stuck at the smallest aperture. I worked them by setting the aperture ring to f16, firing the shutter, setting the aperture to f1.7, firing again, then back to f16, and so on. It took a few of these cycles (about 80), but now the aperture works regularly. I would not be surprised if it got sticky again after a few months of idleness, but I know how to fix it :-).
I am not sure what is supposed to happen in automatic mode, since I am waiting for a replacement battery to test it.