Hi there, so I have an old iMac here (late 2009, 27", 4GB RAM, EMC 2374). I am now trying to do a clean install of the OS by booting from a USB stick. I have both a 10.13.4 stick that I just created and an older 10.11.x stick that I used successfully in the past. Problem is that when I hold ALT during boot I can select the USB stick, but the booting process from the USB stick always dies at around 60% (or maybe 70%, but always at the same point). I can also see the USB stick stop blinking at that point, so that means the iMac does not copy data anymore. I never even get to the OS install screen, it already dies during boot. I tried holding V for verbose mode during boot, but that doesn't seem to work. I tried different USB ports. I tried swapping the 4 GB RAM for 8 GB, no change. Anything else I can do? What is going on here?