I want to change the syncing computer of my iPhone from my dead old PC to my Mac.
Is there any way to do this and still preserve my contacts, photos etc?
I have my iTunes folder from my PC backed up already if that helps.
Since you have the PC already backed up, take the back up drive and connect it to your Mac
Go into your old user account on the PC hard drive, find the "My Music" folder, and drop that over to iTunes on your Mac
OR drop in in the iTunes folder on the Mac hard drive. Make sure you have authorized the Mac with your iTunes account.