iMac Core i7 27" Mid-2011 EMC 2429 HDD went broken

jjarmo wrote:

use Apple Store and download High Sierra. I did do bootable installer "Create a bootable installer for macOS - Apple Support" and start installation. SAME result. It starts fine, reboot 35min, 30min.. and Calculating time! 6hours I did wait nothing happens.

Sounds like you likely have a hardware issue of some sort. Most likely the internal hard drive is failing.

You can try running the Apple Diagnostics to see if any hardware issues are detected, but the diagnostics rarely find issues even when they are confirmed to exist through other tests.

If you can boot into macOS, then you can also try running DriveDx (free trial period) to check the health of the hard drive. Feel free to post the complete text report here using the "Additional Text" icon which looks like a piece of paper on the forum editing toolbar.

2GB partition has High Sierra, 2TB HDD has High Sierra and my 32GB USB has High Sierra. iMAC does not start any of them. I did try Recover, NOW iMAC is totally lost - Utility is only thing opening and seem working. Net install (Reinstall macOS) says no connection to server.

Unfortunately it is not uncommon to have issues with Internet Recovery Mode. Besides the typical networking related issues most people encounter, there have been more reports of Apple's servers not always being available to actually install older versions of macOS even once booted into Internet Recovery Mode.

Since 2GB partition is now High Sierra, Disk utility has lost ability to Restore anything from USB. At the beginning I did make Recovery to USB from Lion - but I cant use it!

I would not put much faith into any instructions for creating a bootable macOS 10.7 Lion USB stick, or even 10.8 Mountain Lion since these installers were not designed by Apple for becoming a USB installer. Any instructions are just hacks which may or may not work to some extent. I tried one for macOS 10.11 El Capitan once & I had mixed results with it.

I've never tried the suggestion by @Grant.

What do you mean by 2GB partition? You need more than a 2GB partition/volume for even a macOS USB installer.

My conclusion is: iMac Core i7 27" Mid-2011 16GB RAM EMC 2429 IS NOT compatible with High Sierra, NOT even with Sierra. It should be! Actually it SHOULD be with Catalina!

macOS 10.15 Catalina is not supported on a 2011 iMac.

I can see that macOS 10.13 High Sierra may have more issues than macOS 10.11 El Capitan because High Sierra is likely using the new APFS file system which is much harder on a hard drive. In fact, the macOS installer will start with the MacOS Extended (Journaled) file system and convert it to the APFS file system (unless it doesn't use APFS for a hard drive).....this occurs even when erasing the drive with the APFS file system. Plus macOS High Sierra may be utilizing the hardware a bit differently than an older OS such as El Capitan which is why you are seemingly only having issues with High Sierra.

And if the problems are getting worse the more you try to reinstall macOS over & over, it makes it even more likely that you have a failing hard drive whose failure is getting worse very quickly from intense use (it was already failing, but these attempts just made it more noticeable). Of course there could be some other hardware issue as well, but a failing hard drive is the most likely. Memory issues is another, although with a 2011 iMac a bad GPU is also a possibility although I have not really seen anything here that would point to a GPU failure, but I also have not seen a lot of details or error messages encountered for these failures either.

I would avoid Lion at all costs since it is just too old. Start with El Capitan if you can and if successful, then create a bootable macOS 10.13 High Sierra USB installer using the official Apple instructions in the following article:

Create a bootable installer for macOS - Apple Support

Keep in mind Macs can be very picky about the drives & even USB sticks used for booting, plus the quality of USB sticks is extremely poor.

I would even recommend installing macOS to an external USB3 hard drive or SSD to see if you can get High Sierra installed onto the external drive & boot the external drive with the full High Sierra installation. If this works, then it further confirms the likelihood of an internal hard drive failure, however, if the iMac still has trouble booting to the external High Sierra full installation it could still be due to an internal drive failure.

jjarmo wrote:

I got my daughter old MacBook Air (Early 2015), with Catalina. All Apple support articles are missing one simple thing - you really need to start El Catalina installation to create installation in Apps (see 3.)!

You could also have downloaded the El Capitan installer using any other computer running any other OS (including a regular Windows PC) as long as it could access the Internet and the download link since the El Capitan installer is available outside the App Store. Then transfer the downloaded .dmg file to your iMac running Lion and continue with extracting the real El Capitan installer from the .dmg file.

Situation where I was, without second macOS machine, required operation would not be possible.

Meanwhile I did try to use High Sierra bootable installation media, it does stuck it to infinite loop calculating time and reason is not APFS conversion.

If you don't have access to another Mac, then that High Sierra USB installer may not be good. The only reliable method of creating a bootable macOS USB installer is by using a compatible Mac and following Apple's instructions here:

Create a bootable installer for macOS - Apple Support

While there may be some other methods, they always require a lot of extra work and may not give you the same install experience.....some may not work at all. Apple has changed the macOS installers over the years so articles from just five years ago may no longer be relevant to the macOS installer you download today even if it is for an older OS.

I did say: For some strange reason iMac Core i7 27" Mid-2011 16GB RAM EMC 2429 IS NOT compatible with High Sierra, NOT even with Sierra. It should be!

A 2011 iMac is compatible with both Sierra and High Sierra. The fact that your iMac does not work with either OS indicates some form of issue with your Mac whether hardware or software. You need to figure out why your iMac is not working with Sierra or High Sierra if you want to use either OS.

Unless it is a bad hard drive/SSD or bad memory, then it is probably not repairable....it is debatable whether it is even worth replacing bad drives/memory for such an old system (don't replace them without confirming a hardware failure first since it would be a waste of money if the item was not the problem). It seems you never bothered to run the Apple Diagnostics or check the health of the internal drive(s) as I previously suggested.

Actually it SHOULD be compatible with Catalina - like my daughters Core i5 MacBook Air is and not only with Catalina! MacBook Air Early 2015 is also competible with macOS Monterey! But Apple decided other way.

How does a 2011 iMac have anything to do with a 2015 MBAir? Other than they both work & are compatible with macOS 10.11 to macOS 10.13 (yes, both are compatible). And why do you think Catalina or Monterey should work on a 2011 Mac? Would it be nice if Apple supported the 2011 iMac with Catalina or Monterey....yes, however, Apple does not support any later version of macOS and it is irrelevant to your original post.

If your daughter has a 2015 MBAir, why weren't you using it to create a bootable macOS 10.13 High Sierra installer using Apple's instructions?

FYI, if you have a spare external USB3 drive, then you could try installing macOS 10.13 High Sierra onto the external drive to see how things go as it won't touch your internal macOS 10.11 El Capitan installation. If the internal drive is the cause of the problem, then installing to the external drive should work. If High Sierra does not install or boot from an external USB3 drive, then you have some sort of hardware issue with your iMac....most likely other than the internal drive(s). If macOS High Sierra installs & boots from an external drive, then most likely the internal drive is bad (yes, even if El Capitan appears to work on it). Of course running some hardware tests with the Apple Diagnostics and the free trial of DriveDx can help determine if there is a hardware issue....there are even other & better ways of testing the memory as well.

jjarmo wrote:

I know how bad is Verbatim and such "USB's" are - so I did use few well working Kingston DataTraveller sticks.

I've had issues with some Kingston Data Traveller USB sticks too. It doesn't take much to cause problems. And using a USB stick for booting a Mac is even worse since Macs are already picky enough about the drives used, so it doesn't take much to go wrong with a drive to cause a boot issue on a Mac.

You may be surprised that your seemingly well working USB stick may not always be working as reliably as you think. I've performed some tests on various USB sticks and discovered bit flip errors on many of them. The errors don't always occur, but they occur much more often than you would expect. I personally do not trust USB sticks, but they are unfortunately a necessity for some types of bootable installers.

jjarmo wrote:

Hopefully I find 1333 MHz DDR3 SO-DIMM (PC3-10600) answer - is there something special. Ones I watched, they sell them double..

The Mac notebooks that you mentioned do not have upgradable RAM, so I'll assume that you're talking about the iMac (27-inch, Mid 2011).

Macs can be picky about RAM, so you generally want to get RAM either from Crucial or Other World Computing – using the tools on their sites to select RAM that they say is compatible with your particular Mac model. I checked both sites and it looks like only OWC has RAM upgrades for your machine.

Other World Computing – OWC Memory Upgrades For 27" & 21.5" iMac (Mid & Late 2011)

Crucial – Apple iMac (21.5 and 27-inch, Mid 2011) iMac12,1/12,2 SSD Upgrades

"Crucial currently does not have any compatible memory upgrades for your particular system"

This, unfortunately, seems to be becoming a bit of a pattern with Crucial and older Macs. But at least OWC carries memory upgrades – for now.

There is a way to get the installer you want or create a bootable installer. It's the MDS app.

You can use the Trial version to download the installer for High Sierra. Then you can click on "Create Bootable Installer" in MDS, select the downloaded installer, have a flash drive prepared and follow the instructions.

Or follow these Apple instructions: Create a bootable installer for macOS - Apple Support

Apple did not ship bootable High Sierra installer DVDs or USB flash drives. There are instructions on how to make a bootable flash drive in an Apple Support article, but they require you to get the regular installer (which, in the case of High Sierra, would mean getting it from the App Store) first.

How to download and install macOS - Apple Support

USB sticks are the least reliable media, but...

APFS won't work for Sierra or earlier, Sierra or earlier needs MacOS Extended Journaled. High Sierra won't work for APFS on earlier Macs.

If all else fails...

https://mrmacintosh.com/how-to-fix-the-recovery-server-could-not-be-contacted-error-high-sierra-recovery-is-still-online-but-broken/

High Sierra “The Recovery Server Could No… - Apple Community

Use http:// instead of https://

https://www.youtube.com/watch?v=ouNQS36dIBw&t=95s

The formula for caos: APFS+macOS High+EFI… - Apple Community

How to recover a Deleted Hard Drive durin… - Apple Community

jjarmo wrote:

Like i5 Macbook Air Early 2015 4GB RAM, this old i7 iMac EMC2429 could.. and should be compatible up to Catalina. My daughters 16" MacBook Pro is latest i7 - will have latest macOS 15 I do hope. Change to ARM is wise from Apple, but soon leaves Intel users in big problems..

I don't know where you're getting your compatibility information, but I'd suggest sticking to Apple's Web site and to MacTracker if you want accurate information.

The iMac (27-inch, Mid 2011) (EMC 2429) does not support Catalina. For that Mac, macOS 10.13.6 (High Sierra) is the end of the line.

You can upgrade Early 2015 MacBook Airs to macOS 12 (Monterey) – but no further. The Early 2015 MacBook Airs came with either 4 GB or 8 GB of RAM (non-expandable), and while I can see 8 GB ones running Monterey, it's not clear how well a 4 GB one (like the one you mentioned) would be able to run Monterey + applications.

Apple only made one 16-inch Intel-based MacBook Pro - the 2019 one. You can upgrade it all the way to Sonoma now, and you will be able to upgrade it to Sequoia when Apple releases Sequoia.

macOS Sequoia Preview - Apple