High Sierra Clean Install from USB after Crash with dual boot

John Galt wrote:

The disc to use will be the one labeled "System Install". I have one around here (somewhere) and will post a picture of it later.

Mac OS X Install DVD:

... and for reference, its corresponding Applications Install DVD which contains AHT — it tends to get nuked when reinstalling OS X:

If you are unable to find the OS X Install DVD and need to purchase one from the used market, I urge caution because these discs are highly system-specific. Not only must you be absolutely certain of the exact model iMac, it gets worse because there are different versions of AHT even within those exact models. For example you will note the above indicates "AHT version 3A214" which was included in the very latest "mid 2011" models. Earlier "mid 2011" models had an earlier version of it (3A213) and "late 2011" models were different still. I believe the difference was for minor changes to the GPU firmware — Apple used two different variants of the AMD GPU with them. Different firmware may also be required for correspondingly minor hardware differences. The point though is that those grey discs are specifically for the Mac they shipped with.

This is the reason I repeatedly state they must accompany those Macs from cradle to grave. At one time in the distant past if we needed to obtain replacements from Apple they would gladly send them to you gratis. Those days are long gone.

To anyone finding this Discussion in the future: please do not use those images unless you are absolutely certain you're discussing the exact same model iMac. They are applicable only to it. Lots of people advertise OS X discs for sale on auction sites, and most of them have no idea what they're talking about. Caveat emptor as always.

I'm posting this from a 2008 MacBook Pro4,1 also running 10.11.6. Not the original HDD (SSD), not the original logic board and not the original battery.

Macs are long-lived - but if you are on the original HDD then you got lucky. Those "Apple" branded HDDs were usually rebranded consumer grade WD drives (the ones in the Time Capsules were WD Green of all things).

Mechanical drives fail - the original poster's is well past the statistically average life-span and their symptoms scream drive failure to me. Your HDD clearly made a pact with infernal powers for immortality.

I agree with @g_wolfman that you probably have a failing drive. Try booting into Internet Recovery Mode using Command + Option + R to boot to the online macOS installer so you can bypass the local recovery mode located on the internal drive.

Here is an Apple article with instructions for accessing the Apple Diagnostics:

Use Apple Diagnostics to test your Mac - Apple Support

Unfortunately the diagnostics rarely detect issues even when a hardware issue is confirmed through other methods, but it never hurts to check.

iMack2022 wrote:

I have created a bootable USB with clean DMG package of High Sierra.

Apple never released the macOS 10.13 High Sierra installer in DMG form. Any High Sierra related DMG files from Apple are only update patches, not a full installer. Here is an Apple article for creating a bootable macOS USB installer:

Create a bootable installer for macOS - Apple Support

You can create & use a bootable macOS 10.11 El Capitan or macOS 10.13 High Sierra USB installer for this Mac depending on what other Mac you may have access in order to create the bootable USB installer.

macOS 10.13 High Sierra -- you need a Mac from Late-2009 to mid-2018

macOS 10.11 El Capitan -- you need a Mac from 2007 to 2015

Or you need to follow @John Galt's suggestion to start with OS X 10.6.7 Snow Leopard.

iMack2022 wrote:

With due respect, Sir.......

No Keyboard command of any combination is working.

It goes straight to the Blue screen.....

You mentioned you were able to access the Option Boot screen, so that did not immediately go to a Windows Blue Screen until after you selected a boot option. Did you actually try Internet Recovery Mode using Command + Option + R? This should bypass all internal boot options which is why I specifically mentioned it.....you should either be presented with an option to connect to WiFi. I don't recall you ever mentioning this particular key combination.

Perhaps try a PRAM Reset (hold it for at least three chimes) to clear the NVRAM in case some setting is forcing the system to always boot to the internal drive or Windows. Then immediately after the third chime, release all keys then quickly press & hold the Option key. When you reach the Apple boot picker menu, try pressing Command + Option + R to see what happens (I'm trying to keep the system from booting to the internal drive at all in case it modifies the NVRAM thus negating the effect of the PRAM Reset).

@John Galt's suggestion for using the original OS X Restoration DVD is an even better option if none of this works.

g_wolfman wrote:

... I can't think of any PC hardware + Windows combination that would last more than 13 years before failing.

Posted from that iMac, which also happens to be using its original hard disk drive. It's fast enough. It also boots Snow Leopard and Ubuntu Linux.

I have models that date back to 1985. It has been my experience that Macs last essentially forever.

Now all I am seeking is how to get to the boot option and clean install Mac OS only.

A mid 2011 model iMac shipped with OS X on optical media (two grey DVD discs) that must accompany those Macs from cradle to grave.

You need those discs. Find them.

Given the symptoms you describe, I think you have bigger problems - possibly a failed/failing hard drive (I'm guessing it is the original mechanical HDD?) with a bad boot sector.

You might want to boot into Apple Diagnostics and see what it reports before messing around with attempts at an OS reinstall.

Sure. There are lots of vids for both the 21.5" and 27" 2011 iMacs. For example, https://eshop.macsales.com/installvideos/imac_mid21_2011_ssddiy/ and https://eshop.macsales.com/installvideos/imac_mid27_2011_ssddiy/

But if you are going to dive into the computer's guts, you may as well replace the HDD with a SSD. At least the performance would be slightly less abysmal. And, you know, if it is a boot sector failure on a mechanical HDD, it's probably unusable so trying to reinstall the OS is just going to waste your time and frustrate you.

Find another Mac you can build a High Sierra bootable USB installer on, do that, replace the iMac drive with a SSD, and install High Sierra from the USB - would be my advice.

If Cmd+r or Option is not going to the recovery partition or the firmware bootloader respectively...were you running High Sierra on the Mac half of your dual boot, or something that pre-dates recovery partitions?

Alternatively, if you are going to give up on this computer (justifiable) and go to another OS, I'd recommend Linux. I can't think of any PC hardware + Windows combination that would last more than 13 years before failing.

iMack2022 wrote:

Question remains same, How do I get to Boot selection?

The same way... press and hold an Option key with that disc already inserted in the optical drive when starting the iMac with another finger. It will appear as a bootable device bearing a shiny round "disc" icon instead of the square-ish "hard disk drive" icon.

The disc to use will be the one labeled "System Install". I have one around here (somewhere) and will post a picture of it later.

Your HDD clearly made a pact with infernal powers for immortality.

😆

It's not just that one though.

It never occurred to me to check, but that iMac's HDD happens to be a Seagate Barracuda ST3500418ASQ. Another, similarly aged iMac uses a Western Digital Caviar Black WD1001FALS. They were the last Macs I bought with spinners, well over a decade ago.

I have lots of other hard disk drives in use for Time Machine backups in addition to many Time Capsules (several different models). I don't happen to know what kind they have. I don't know if that information can be determined easily, but I might look into it. As I recall Apple used some kind of server-grade drives, but I could be wrong.

None of these have ever failed. The only HDD failure I have ever experienced was an OWC 2.5" drive which I seem to recall used a Seagate mechanism. It was replaced under warranty many years ago, and remains in service to this day.

I am reluctant to attribute that success to luck. If anything's a factor, it's probably the lack of any garbage products people are so fond of installing — things like "cleaners" / "anti-virus" and whatnot are strictly prohibited by corporate policy (mine).

I also prohibit the installation of anything Google.

Coincidence? I don't believe in that.

Took a Time Capsule that completely died apart a year or so ago - definitely a WD Green in there. Kind of makes sense as the use pattern for Time Machine backups is actually amenable to a lower power consumption drive. Had they been more NAS-like in their intended R/W patterns, they probably would have used WD Red since Seagate Ironwolf drives weren't that big back in the day.

Barracuda sounds about right for a consumer-grade drive. Must admit the WD Black is a bit of a surprise - was that the higher-end iMac of the day?

Also, I now clearly see that you are the leader of an infernal Hard Drive cult, and WD Noir is obviously the Black Knight - Paladin of Sin...get thee behind me, spindle!

There was nothing special about that iMac. It was purchased like any other, so I doubt it's unique.

Did you replace the drive in that Time Capsule? Was that its only problem? If it's just the drive they're replaceable, but the power supplies allegedly don't last forever either. Fortunately I've never had to replace either one but I'm willing to try.