Chosen Solution
Randomly invested in a $20 not powering on iMac A1125 3.06GHz Core 2 Duo with I’m guessing 4GB RAM (2 x 2G and Apple states capable of 8GB max though one seller I found has a 16GB max option), NVIDIA ? and 1TB HD with one other I can’t read option noted (see image in FB link below). Seems like a neat upgrade from the free eMac’s with Snow Leopard installed. https://www.facebook.com/photo?fbid=4832… Read online what I could find, unplugged and held down the power button for ~1.5 minutes, plugged back into the wall 120VAC outlet and then pressed the Power Button to observe the Apple Icon with a progress bar that slowed down progressively to about 3/4’s the way stuck and then the iMac powered off after ~5-10mins. That’s all the computer would perform. Read this link, https://discussions.apple.com/thread/847…, where nothing appeared to do anything other than the #3 (Resetting your Mac’s PRAM and NVRAM) restarted the computer when I’d hold down the keys and #8 automatically performed, what holding down the
Do you have a second mac system which you can connect to this system via FireWire? Understanding the Applications for Target Disk Mode What you want to do here is reformat the drive to GUID journaled file system and then setup the proper OS onto your system. OS-X El Capitan 10.11.6 is the highest this system can support. Get the needed OS installer from here How to get old versions of macOS and follow this guide to setup a bootable OS installer if your system is running something newer on your second system How to make a bootable OS X 10.11 El Capitan installer drive