OK, here’s my summary of this forgettable chapter in my exceedingly-mundane life:
The solution for El Capitan’s installer to run was to set the computer’s date to 1 day after the app-release date, so I tried 2015-12-12. The Sierra installer then ran, but froze with an empty progress bar and 7 minutes remaining on the clock.
Creating an install disk failed with Terminal, but worked using "Disk Creator", a free app. However, the resulting USB-stick installer failed to show up in Sys Prefs / Startup Disk and when booting holding down "Option".
The help I received here involved being instructed to do things I’d already done… repeatedly, unfortunately. Thankfully, I persisted:
So far all my efforts had been conducted from within multiple 10.12.6 partitions created from an image I made on 2017-08-13.
I tried installing an old image of 10.8.5 Mountain Lion, from which I was able to run the installer (yay!):
The 10.12.3 installer only worked from 10.8.5 on the EVO 840 & later, after I’d swapped the drives out, the EVO 850 partitions. Several graphic anomalies were present:
Random block-shading issues on the info bar.
No arrows for scrolling the destination-drive window (clicked where they should have been).
No time-remaining readout, but it still worked.
Now that I had working baseline installations of 10.12.3, I tackled the 10.12.6 combo-update challenge:
It wouldn't install from or on 10.12.3 fresh-spinner installations. It only worked:
From 10.12.6 partitions created via the 10.8.5 840 & 850 EVO SSD installs.
From 10.8.5 partitions.
On 10.12.3 installs created via the 10.8.5 840 & 850 EVO SSD installs, with the caveat below.
Disconnecting from the internet prevented a "couldn't complete - updates available" message from appearing, which previously resulted in failed updates from within 10.12.3 installs.
End of saga. Amen.
I was dealing with the biggest drama I’ve encountered with my fish tanks since 1987 throughout this, where I came close to losing all my long-finned While Cloud Mountain Minnows, a strain I’ve refined for 15 years now. Repeated dis and re-connection of my power filter canister (20+ times, and involving dis and re-assembly at the other end of the house), and the shenanigans involved in repairing the impeller, had me at wit’s end and physically-worn-out. Long, involved story, but I mention this only to provide a little context as to why my usually-pathetic sense of humour has been absent from this thread; I
needed to sort this out, preferably before the fish died and my impending 50th (none of you is invited, ‘cause I’m not having a party and you live too far away!). I did arrange for my brother to come over last night for a week-early get-together with two of his friends, but alas, he failed to return my reminder calls all week (didn’t want to buy food for them in case he didn’t roll up as I don’t have a freezer), and didn’t show up or call last night. I might’ve had better luck inviting you, my US buddies, after all!
Anyway, thank you so much for trying to help, Mike and Sir Markus. I sincerely hope that anyone running into this thread finds my solutions useful. The extent of the problems I encountered with these installations wasn’t something I was able to find a match for on the GoogleNets.
Oh, and my brand-new WD Gold HD has behaved strangely (half a dozen bizarre symptoms) throughout this effort. The store insists I take a taxi to return it (no other way, apparently), after which the wholesaler will pick it up and “test” it. If, under
its conditions, it deems the unit faulty, the warranty will be honoured. Lame, especially at the price of the Golds and considering the extended warranty, which I figured would involve a straight swap for a new one. Oh well, at least most of this saga is over! Phew…
Thank you again, peeps. Love you guys.