Raymond, I don't know if this will get you into the service menu of your pz85 or not but here is how I access the service menu for my pz800.
Enter the service menu by taking the volume all the way to zero, release, then hold the VOL- button on the front of the TV set and press INFO three times on the remote. Release the VOL- button on the front of the TV set, and after a couple of seconds the service menu will be displayed in the top left corner of the screen.
To exit the service menu, either press Power on the remote or on the front panel of the TV set.
Entering the service menu can be very dangerous so make sure you write down all values or use a camera to take pictures of the screens before you make any changes. Good luck.
The measure of a man's character is what he would do if he knew he never would be found out.