Exactly! It seems sort of like a combination of open firmware commands getting confused with single user mode, which still won’t be useful if the computer won’t start up at all.
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Mac Minis won’t boot after (I assume) failed windows installs. Can’t get MacOS back.
- Thread starter Tony Danger
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So long story short, do you think the firmware is corrupted and is there a fix ? I would have assumed the windows installer wrote to a hidden disk partition , but if he removed the disk and it still does not work, then thats clearly not the case !
Strange things can happen in startup process, including resolution negotiation between the computer and the monitor. It may end up with a temporary resolution for boot process (which is not necessary the monitor's default 1920x1080) that the Mac can't continue to display the Boot Manager or the Internet Recovery or any thing that needs to be displayed on the monitor during pre-boot.
You may not find this issue in normal boot. Because after your mac finishes booting, it will negotiate with the monitor again. But this time, the OS in the Mac is already loaded and can do better negotiation with the monitor to get the default resolution which is set in Displays Preferences pane.
But your Macs won't finishes the booting because the OS inside is somehow can't be used. And it may be stuck at a monitor resolution that the Boot Manager can't be displayed.
This kind of problem can happen in both Macs and PCs. For example, the Mac in this thread won't boot when the monitor is connected using Display Port but will boot fine with HDMI.
Will Not Boot with New Display Monitors!!… - Apple Community
So I'm still suspecting the monitor and/or the monitor connection. If you can't try another monitor but it has other connections, I would try it.
Try using internet recovery mode with internet connected, by holding option, command, R at bootup until you see the globe is running instead of the apple symbol. When it loads then use disk utility and try first aid on the drives. When completed go up to the apple and set your restart to your existing hard drive and reboot. If still no go, then try Option-R recovery, when it comes back to recovery window go to terminal on top menu bar and type csrutil disable, then press enter and put in your password. then click apple symbol and restart. This will turn off the System Integrity Protection on your mac. I find older macs are buggy with this on. You can reactivate later by doing it in recovery mode again but type csrutil enable.
I'd still like to know if the OP has been using an Apple keyboard, but they've obviously lost interest in this problem and aren't going to answer any questions.
I’ve not lost interest, I’ve just been busy. Also I can only say this so many times, the boot commands don’t work, EXCEPT Reset NVRAM. So people who keep reading my post here or on Reddit, then say use X or Y boot command is getting old! I'm not trying to be rude and apologise if this comes across as so, but if folk don’t read my post then their support isn’t going to be helpful.
Back to the issue:
Windows wired keyboard. Don’t have an Apple keyboard available.
Also I’ve got two more being sent to me this weekend in a working condition. They have all been sourced from a school clearance and have Windows 7 installed. These two faulty ones did too before the previous owner tried to install windows 8 and messed them up.
Back to the issue:
Windows wired keyboard. Don’t have an Apple keyboard available.
Also I’ve got two more being sent to me this weekend in a working condition. They have all been sourced from a school clearance and have Windows 7 installed. These two faulty ones did too before the previous owner tried to install windows 8 and messed them up.
But the OP can reset NVRAM with the keyboard. That means the Alt and other related keys are working. And to get to the Boot Manager requires only Alt key pressed.
My thought process is wait to get these two other machines that will boot into windows 7 and see if the boot manager exists / works on those. If it does then try cloning their drives onto the faulty machines and see if I can get them going.
Just add more info, a lot of Windows keyboards from Microsoft and Logitech can only reset the NVRAM ONE time only, for a full NVRAM reset you need to continuously keep pressing CMD-Option-P-R until the fourth beep - reseting at least 3 times, continuous sequence. My advice is to deep reset it 4 times, only stop pressing CMD-Option-P-R after the 5th beep.
You can also try to boot withot the RTC battery installed, this makes the PEI to completely bypass the NVRAM volume inside the BootROM with Macs this vintage. This would be the second thing that I'd do.
Edit: make the deep NVRAM reset procedure clear.
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While at this, measure the voltage of the BR2032 battery with a voltmeter/multimeter and replace it with a real Panasonic BR2032 if the battery have anything less than 3.00V, the RTC is really important for Macs and if it became stuck or non-operational you'll start to have sleep KPs and then bootability problems. RTC starts to misbehave with voltages below 2.9V, and becomes stuck at 2.75V.
Since the factory voltage of a BR2032 is well over 3.2V and takes several years of usage for it begin to drop and then is a fast downhill, I'd replace it if is below 3.2V, too much work to replace the RTC battery with a Mac mini.
Also, never replace the mini BR2032 with a CR2032B for long term usage, ok for short tests/diagnostics, this is critical with Mac minis (and Mac Pros since the RTC holder is right below the GPU heatsink), the internal temperature of a mini will cook a CR2032B in weeks, different chemistry than a BR2032. The Panasonic BR2032 is rated for operating temperature of up to 85ºC, while CR2032B are usually rated to 65ºC.
Since the factory voltage of a BR2032 is well over 3.2V and takes several years of usage for it begin to drop and then is a fast downhill, I'd replace it if is below 3.2V, too much work to replace the RTC battery with a Mac mini.
Also, never replace the mini BR2032 with a CR2032B for long term usage, ok for short tests/diagnostics, this is critical with Mac minis (and Mac Pros since the RTC holder is right below the GPU heatsink), the internal temperature of a mini will cook a CR2032B in weeks, different chemistry than a BR2032. The Panasonic BR2032 is rated for operating temperature of up to 85ºC, while CR2032B are usually rated to 65ºC.
I'm guessing it should be safe to use a CR2032 during setup / diagnostic etc while testing and trying to get these machines running?
Like I wrote, you can use a CR2032 for tests/diagnostics, but don't use it besides that, you will have to replace it the moment that the internal temperature goes over 65ºC, a very common occurrence with minis when doing compiling/rendering/macOS installs or restores.
Some people say that you can use a CR2032 without problem, but I bet that these are people that are somewhere with low indoor temperatures or never do anything to tax the processor.
Well good news. The new ones arrived and can be booted into recovery! So time to get one running then clone the drive.
I ended up just putting linux mint on them all. All working great now and can safely browse the web with modern browsers.
Can vouch for this. I did this for a 2012 Mini for a quick fix and forgot to change it. I was having all sorts of problems with sleep and just getting the damn thing to boot if shut down and reckoned the logic board was on its way out. Just reading this gave me an aha moment and I pulled out the battery - dead, zero volts or current. This is with a machine that probably never went over 65ºC if iStat is to be believed.
Just a pity that BR-2032 batteries are several times the cost of CR-2032 but at least it isn't proprietary, as Apple has used in the past.
Put the drive in from one of the working ones and it booted. So I cloned the drive and all seems well. I can now get into boot selector and internet recovery etc on all 4.
A colleague wanted to sell his trashcan and could not do a fresh install on the internal drive (got always an error the drive could not be used). He used an external drive for the install that went without a problem. I used Carbon Copy Cloner to clone the external to the internal and starting up from the internal, performing hardwaretest went flawlessly!
You can try to do Mac Os recovery but using the internet. Option shift command R- go to disk recovery mode and try it that way. I had to do it on my 2014 mini...to wipe out the drive to reinstall mojave os and now no problems.
Use macOS Recovery on an Intel-based Mac
Learn how to use macOS Recovery on an Intel-based Mac.
support.apple.com
2011 Macs support Internet Recovery. It first became available via a firmware update on 2010 Macs and then has been available since.
Call them anyway, the worst thing that can happen is nothing. Up until last year I have a 2010 MacBook and a late 09 iMac and called and got help several times on both. Take a couple of minutes and try never hurts. If you don't ask the answer is always no. lol