iMac late 2006 / 2 GHz Intel Core 2 Duo /4 GB 667 MHz DDR2 SDRAM /Mac OS X Lion 10.7.5
2016 21.5 inch iMac. I suspect either HD or some other hardware issue. 3-5 minute start up vs. 45 sec. for my 2006. Tried all the Utilities i could to repair. Eventually so bad only Safe Mode. Tried to install the newest OS Sierra , Nothing.
They were nice enough to take it back since i wrestled with past the 2 week full return policy ONLY because i stated it was faulty right out of the box.
So when i get the time i`ll try the hack install of el capitan. Worst case is back to square one, still have an original snow leopard disc
Probably bad HD or Fusion drive. I installed about 250 of them under contract last year at one site and we didn’t have any issues. Hadn’t heard about many others in the local consultant community or online so I think you just got a bad one. Surprised you didn’t just get another one.
As for running anything later than 10.7.5 on that thing... Don’t. Intel screwed up the memory controller on that generation of chips and it can’t address much more than 3GB of RAM even with that full 4GB worth of chips you have in it. I had that one, did the same hack (at the time to 10.9) and wished I hadn’t. 10.9 and later is very unhappy with 4GB and less RAM if you do anything but extremely light usage; it really wants 8GB or more.
snow leopard forever ...