Power steering not working

Hello,
Hoping someone here can help me figure out the current problem with my car.
Six months ago it blew a head gasket on the highway, driving home from work. Had it towed home and did not touch it for six months. I recently got around to replacing the head/intake gaskets and got it running again. Went to take it for the first test drive and there is no power steering. At first I thought maybe it was just something stuck from sitting unused for six months and thought it would free up at some point during the drive, but unfortunately that did not happen. I have taken it on multiple drives since around around the neighborhoods in my town and still no power steering. I do not know a whole lot about power steering systems and have never had to work on one or ever had any issues with one. I checked the fluid res and its full with fluid and no signs of a leak. I came across a YouTube video showing how to bleed the system by putting the front end on jack stands and moving the wheels left and right multiple times. That also did not work. I have never had any issues or warning signed with the power steering prior to the gasket failure and parking it for six months. I do not understand how something like power steering system can fail while sitting parked, unused for months. I would expect such parts, like most all others to wear out and fail from daily use.
Anybody have any ideas what could be the problem here? Or any tips to help me with troubleshooting and narrowing the problem down to a particular system component to begin the search for the problem? Any help would be greatly appreciated.

Thank you,
Eric