Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

wescx005

macrumors newbie
Original poster
May 16, 2019
3
1
Dallas, TX
Today
Dallas, TX
#1
Good Morning- After about 3 days of trial and error I need help.

Alittle background info. I have acquired what I believe based of internet research is a early 2007-2009 imac All in one unit, it has the black back panel (not the silver aluminium design). It has USB, RJ45, firewall, headphone jack in the lower right corner however NO THUNDERBOLT which leads me to believe its an early design. It has a very large screen but it does not boot. It powers on, chimes and after about 2 minutes I get the folder with the question mark which again reading says the mac cant find a boot disk.

What I have done :

Reset the PRAM, did this successfully holding down the command, option and P+R combo on power on.
I have downloaded OSX El Capatian and created a bootable USB from the .dmg image file using my windows machine. I plugged in the usb into the mac and held down the 'c' key and it recognized the USB with a yellow usb icon on the screen and the arrow below the icon. I clicked it and it spun its wheels however after 2 minutes or so of loading I get the stop sigh / circle with slash through it. Upon more research seems that symbol means a firmware / hardware mismatch with the IOS (IOS wont support that version of mac. So I downloaded Lion and snow leopard and those again held the 'c' at bootup and those versions gave me the grey apple symbol after about a minute and a progress bar at the bottom but after another minute or so the apple symbol changed to the circle slash again. This is my first mac, but I am a IT admin so I just dont know enough about the mac to determine if this is hardware or software. For example if the hard drive is bad on this, could it cause that symbol ? I was under the impression even with a bad hard drive if you have a bootable CD or USB it should at least boot all the way to the desktop from that medium. Please help. I will send you a case of beer for anyone who can assist. I haven't opened it and do not know the history and before i start popping off the screen I wanted to ask here. Thanks in advance !
 

DeltaMac

macrumors G5
Jul 30, 2003
13,425
4,392
Delaware
It's sometimes useful to know that making a Mac disk bootable, in Windows, is not always successful.
You may get to the point where the disk (maybe a USB flash drive) seems to be complete, and correct.
What windows app were you using to do that task?
I am not familiar with ANY method that works from the Windows command line, for example.
But, the final test is: Does it boot a Mac that should be compatible with that macOS system?
So far, nothing that you have tried has been successful.
Just to make this more clear, the flashing folder means that the hardware is searching for a bootable system.
The "Prohibited" symbol, on the other hand, means that there is a bootable system, but there's something wrong with the boot software, maybe something missing, or there is a corrupted file, or maybe the macOS version is just not compatible.
The silver and black iMacs, with the black back, should boot to any of those systems that you tried, ASSUMING that the bootable drive is correctly created. That can be the problem that you have, just nothing that you have tried from Windows is making a properly complete, bootable installer.
If you have NO other Macs - where are you downloading those various installer apps from?

You might want to find out exactly which model iMac you have. It's easy to find that by getting the serial number (it's on the bottom of the stand), then going to a site that allows searching for serial numbers, then reporting the Apple device with that serial number.
Good one here - https://everymac.com/ultimate-mac-lookup/
 

wescx005

macrumors newbie
Original poster
May 16, 2019
3
1
Dallas, TX
It's sometimes useful to know that making a Mac disk bootable, in Windows, is not always successful.
You may get to the point where the disk (maybe a USB flash drive) seems to be complete, and correct.
What windows app were you using to do that task?
I am not familiar with ANY method that works from the Windows command line, for example.
But, the final test is: Does it boot a Mac that should be compatible with that macOS system?
So far, nothing that you have tried has been successful.
Just to make this more clear, the flashing folder means that the hardware is searching for a bootable system.
The "Prohibited" symbol, on the other hand, means that there is a bootable system, but there's something wrong with the boot software, maybe something missing, or there is a corrupted file, or maybe the macOS version is just not compatible.
The silver and black iMacs, with the black back, should boot to any of those systems that you tried, ASSUMING that the bootable drive is correctly created. That can be the problem that you have, just nothing that you have tried from Windows is making a properly complete, bootable installer.
If you have NO other Macs - where are you downloading those various installer apps from?

You might want to find out exactly which model iMac you have. It's easy to find that by getting the serial number (it's on the bottom of the stand), then going to a site that allows searching for serial numbers, then reporting the Apple device with that serial number.
Good one here - https://everymac.com/ultimate-mac-lookup/


Delta Mac- Great info, about looking on the bottom of the stand, that's the ONLY place I haven't looked. I do not have the machine with me but will check at home.

To answer your questions I have downloaded the .dmg files from different places on the web as I cant find the full installs on the apple website (only patches and updates). I am using a program called Anyburn http://www.anyburn.com/tutorials/burn-dmg-file.htm to create the USB boot stick. I haven't tried using it to make a DVD but I can tonight. I just figure it would be easier with the USB stick, however I have seen where not all memory sticks are the same and cant really be validated as you said. Once thing I did do is I bought a oem disk off amazon for OSX El Captain in case I was fighting a USB issue with format or bad image. Hopefully I will get the disc this weekend. A question I had though is will a bad / faulty Hard drive cause the circle / slash symbol even though your booting from USB / DVD... Kinda like windows setup, you may be able to boot from the setup disk and install the OS but if you have a issue with your hard drive you will encounter an error at some point during the setup.

But for some reason on Macs I was under the impression you can boot all the way to a GUI from the bootable even though your regular boot disk is toast. Is this correct? I am just trying to eliminate things here.

I guess what I am trying to validate is the prohibited symbol I get while booting from the USB is it USB related or do I have bad hard drive inside the mac.

sorry if its long winded but wanted to give as much detail as possible.
 

DeltaMac

macrumors G5
Jul 30, 2003
13,425
4,392
Delaware
The "prohibited" symbol is almost always a software issue:
Something wrong with the boot, maybe a corrupted boot file, or some problem with the boot drive - or something as simple as a system that shows up as a possible boot choice, but isn't compatible.
The other "flashing folder" is either a missing boot system, or perhaps one that is not "blessed" properly. I think Windows can have a similar issue.
The flashing folder, or the prohibited symol might even have the same fix, which is to boot from a drive that is properly setup, and has a boot system compatible with your iMac.
Did some searching, as fixes for this issue (making a bootable macOS installer on Windows) changes from time to time, and I needed to find out if there are alternatives.
Here's something that should work for you... https://pureinfotech.com/create-macos-bootable-usb-windows/
(short story, download the "TransMac" app.)

(note -- Apple has not provided ANY installer DVDs, or other optical media, and have not included ANY software media with any new Mac since the release of Lion, 8 years ago. Lion and later OS installers are ALL downloads.)
So, there are no "OEM" disks available from Apple (although you can still purchase a OS X 10.6.3 (Snow Leopard) install DVD from Apple, which was never updated, even to the most current version of Snow Leopard, and same DVD sold for the last 9 years.
That doesn't say that the DVD that you ordered won't work. But, it's not an OEM DVD, and simply one that someone made to sell to you - probably the same company that offered that for sale through Amazon.

Can a failed hard drive interfere with booting, even to an external known-good boot drive?
Sure. In a service shop, I have to occasionally (it's kinda rare) open up a Mac and remove the internal drive before I could get that Mac to successfully boot ANYTHING. Not saying that will be needed for you. I think all you really need is a known-good boot disk - and so far, I don't think you have one.
 

wescx005

macrumors newbie
Original poster
May 16, 2019
3
1
Dallas, TX
The "prohibited" symbol is almost always a software issue:
Something wrong with the boot, maybe a corrupted boot file, or some problem with the boot drive - or something as simple as a system that shows up as a possible boot choice, but isn't compatible.
The other "flashing folder" is either a missing boot system, or perhaps one that is not "blessed" properly. I think Windows can have a similar issue.
The flashing folder, or the prohibited symol might even have the same fix, which is to boot from a drive that is properly setup, and has a boot system compatible with your iMac.
Did some searching, as fixes for this issue (making a bootable macOS installer on Windows) changes from time to time, and I needed to find out if there are alternatives.
Here's something that should work for you... https://pureinfotech.com/create-macos-bootable-usb-windows/
(short story, download the "TransMac" app.)

(note -- Apple has not provided ANY installer DVDs, or other optical media, and have not included ANY software media with any new Mac since the release of Lion, 8 years ago. Lion and later OS installers are ALL downloads.)
So, there are no "OEM" disks available from Apple (although you can still purchase a OS X 10.6.3 (Snow Leopard) install DVD from Apple, which was never updated, even to the most current version of Snow Leopard, and same DVD sold for the last 9 years.
That doesn't say that the DVD that you ordered won't work. But, it's not an OEM DVD, and simply one that someone made to sell to you - probably the same company that offered that for sale through Amazon.

Can a failed hard drive interfere with booting, even to an external known-good boot drive?
Sure. In a service shop, I have to occasionally (it's kinda rare) open up a Mac and remove the internal drive before I could get that Mac to successfully boot ANYTHING. Not saying that will be needed for you. I think all you really need is a known-good boot disk - and so far, I don't think you have one.


Perfect thank you and I agree. Tonight I will try again and validate my system with the first link you provided. Thanks again for the help and I will let you know my findings!
 

DeltaMac

macrumors G5
Jul 30, 2003
13,425
4,392
Delaware
Not sure what you mean by "validate my system". That link provides you with a way to fully identify which Mac you have, by entering the serial number. 'Tis purely for information, so you can be sure of the exact Mac model that you have.
 

wescx005

macrumors newbie
Original poster
May 16, 2019
3
1
Dallas, TX
Not sure what you mean by "validate my system". That link provides you with a way to fully identify which Mac you have, by entering the serial number. 'Tis purely for information, so you can be sure of the exact Mac model that you have.

Correct that is what I meant, I will use the link and reference my serial number to tell me (validate) exactly what I am working with. Thanks again for the help!
[doublepost=1558039248][/doublepost]
Not sure what you mean by "validate my system". That link provides you with a way to fully identify which Mac you have, by entering the serial number. 'Tis purely for information, so you can be sure of the exact Mac model that you have.
one more question. I have a external WD 'My Book' USB drive. Is it better you think to use this instead of the USB stick ? Perhaps using a real drive instead of a USB flash drive that sometimes may be flaky will give me a better result?
 
  • Like
Reactions: DeltaMac

DeltaMac

macrumors G5
Jul 30, 2003
13,425
4,392
Delaware
Yes, the WD drive would likely give you a better result, particularly if it is an SSD.
You can add a partition to the WD drive. 8GB would be a great partition to use for the bootable installer.

However, I have a box with about 30 flash drives, some never used, and about a dozen bootable with different Mac OS installers. I have (4?) different USB externals with various setups of bootable systems, and bootable installers, which are setup for a variety of support work that I do daily. I have a single 250 GB SSD with 18 partitions, all different OS X installs.
So, I keep a lot of options for booting or wiping/installing on just about any Mac sold in the last 20 years.
I have experimented - a lot - with different setups. I can install on a USB storage, and have it ready to use/boot in less than 10 minutes. However, most any USB flash drive works, but the preparation time is much longer, sometimes more than 40 minutes. I sometimes give those installers out to customers, after doing upgrades for them. Gives something that the user can work with, in case reinstalls need to happen :D
 

wescx005

macrumors newbie
Original poster
May 16, 2019
3
1
Dallas, TX
Success!!!
Well pretty much anyways I have successfully booted to a Mountain Lion image from the WD standalone drive and currently formatting the internal drive. What I did in case someone runs into this but DeltaMac was spot on.

First of all I ditched the USB 32 GB flash drive I was using since none of the various images was booting. I flipped over the unit and found I have a https://everymac.com/systems/apple/imac/specs/imac-core-2-extreme-2.8-24-inch-aluminum-specs.html

that being said it latest OS supported is El Capatian. I tried to use that image first, it booted, past the grey Apple sign and actually loaded a progress bar below it and got to about 75% before the prohibit symbol came back. BUT it got further than last time using the same image using the Flash drive. So I figure latest updates / firmware were not done so I went back to what I know works (what it was shipped with) which was Lion according to the website. Sure enough booted lion from the WD and it dumped me right into the recovery screen. Gives me options to recover, disk utility and fresh install of Lion. I did use the transmac instead of the other utility, so not sure if it was the USB flash disk or the other app or combination of both that was messing it up. Glad to see the GUI and I can probably take it from here but thank you again Delta Mac. I will probably dump in more RAM as that is an easy bang for buck performance boost but other than that I think I'm good to go!!
 
Last edited:
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.