Hi guys I need some help.

I have read all the posts on the transistors to repair a PGM3 and have searched the parts numbers but can't find them with the "Z" on the end, I can find them without the "Z" is this the same?
Can anyone confirm the part numbers and where they can be purchased.
Also as my power valves are not working at all how do I first test the power valve servo motor to make sure it cycles and that this is not the problem?
The valves are not tight and can be moved in both directions from hi to low.

Any direction would be much appreciated.