When you connected the dead Mac hard drive to a PC, you must have run a Mac recovery software on windows host to recover all your data from a dead Mac hard drive. But as you said when you connected your Mac to another Mac it won't show up so there might be chances that your hard drive may have received any physical damage. If a hard disk is physical damaged and data is to be recovered then it must be sent to a certified data recovery lab.
Please read more on [http://www.stellarinfo.com/mac-data-recovery-on-windows.htm|how to do Mac file recovery on windows computer system]