About the service it's very fast and reliable. About the manual the quality is high enough to read even the tiniest details on the wiring diagrams so you can't ask much more than that, let it alone for a manual of a product from 20 years ago. Thank you, very satisfied.
This is a great and complete Service Manual for the Sharp GF8585HB. Giving full and detailed technical insight. Good to find these manuals online.
Text excerpt from page 12 (click to view)
5.4. Dial Lock
You can prevent others from making a call to any number except the one pre-programmed in the memory of the EMERGENCY button. Once you locked the dialing buttons, even emergency numbers cannot be dialed. Only incoming calls are accepted until the dial lock is canceled. Before using this feature, we recommend storing an emergency number in the memory of the EMERGENCY button. Even if the dialing buttons are locked, the number stored in the button can be dialed.