At this “Remove logic board” guide iMac Intel 21.5" EMC 2805 Logic Board Replacement step 65, I’m not seeing any PCIe socket. Does this mean if you bought an iMac with HDD you cannot add PCIe-based storage module to it later? I see in this guide, there can be a HDD with the PCIe-based model.
I’m completely confused about removing the connectors to the screen. It looks to me as though the battery could come out with the screen still attached. How am I wrong?