My iMac has broken and I'd like to transfer my data to an existing Mac Mini without restoring the whole Time Machine backup. I started with my iTunes library and that worked fine, but Photos is causing a problem. Firstly, I copied the Photos Library from the TM backup to an external drive. Then I opened the Photos app and pointed it at the library on the external drive. I had not used Photos on this Mac previously. A message appeared telling me that the library would of have to be repaired. This took quite a while to do, but when it finished only a tiny proportion of my photos were visible. I followed the same proceans again with exactly the same result. The underlying data seems to be there as the Photos library is 650GB in size. Is there another way of restoring this?