Late 2012 Mac Mini Display Issues

[WPS408]

My late 2012 Mac Mini 2.3 Ghz i7 is having weird display issues I haven't seen before and I'm having a hard time finding relatable issues online. When I start it in normal mode it is very pixelated with green, yellow, and blue square dots everywhere and unresponsive. However, when started in safe mode It seems fine. Has anyone else had this issue and, more importantly, does anyone have a fix? I have gone through the normal routes of disk utility, nvRAm reset, SMC reset, and reload OSX. It should be mentioned that this happened with High Sierra and then I did a clean install of Mohave, still have the same issue. Thanks in advance to any help the forum can offer!

 

[Miat]

Not sure if it is relevant to this problem, but have you replaced the PRAM battery in the last 2-3 years? If not it might be worth trying, given the age of the machine.

Very cheap to do, if you do it yourself. Though, being an Apple machine, of course you have to almost completely dismantle the damn thing just to get to the battery.

Make sure you get the right battery – BR2032 coin-cell. Not the much more common CR version.

https://www.ifixit.com/Guide/Mac+Mini+Late+2012+PRAM+Battery+Replacement/11725

 

[Richard8655]

My thoughts are that if the problem disappears in safe mode, there must be some additional software or font set loaded and used during normal startup. Are you sure you don’t have any user installed graphics, background software, or startup procedure running that you may not be aware of?

 

[Fishrrman]

PRAM battery will make no difference. None.

OP:
If safe mode works, I suggest this:
- Create a NEW administrative account in "users & groups".
- this is "for test purposes only", don't add anything to it other than the stuff that Apple puts in there.
- Log into this new test account.
- Are the results same as a safe boot (i.e., "good")? Or are they bad, as your regular account?

If the test account is consistently "good", then, as Richard mentioned above, it's probably something in your regular account (software that you added) that is the source of the problem.
Could most likely be kernel extension (kext), startup item, etc.

One other question:
Have you added RAM to the Mini at some point?

 

[WPS408]

Not sure if it is relevant to this problem, but have you replaced the PRAM battery in the last 2-3 years? If not it might be worth trying, given the age of the machine.

Very cheap to do, if you do it yourself. Though, being an Apple machine, of course you have to almost completely dismantle the damn thing just to get to the battery.

Make sure you get the right battery – BR2032 coin-cell. Not the much more common CR version.

https://www.ifixit.com/Guide/Mac+Mini+Late+2012+PRAM+Battery+Replacement/11725

[doublepost=1538942013][/doublepost]Hello Miat, thanks for the reply. Yes, I have replaced the battery and it is still doing this.
[doublepost=1538942541][/doublepost]

My thoughts are that if the problem disappears in safe mode, there must be some additional software or font set loaded and used during normal startup. Are you sure you don’t have any user installed graphics, background software, or startup procedure running that you may not be aware of?

Hi Richard, thanks for the input. I have done a total wipe and a clean install of High Sierra and then Mohave and the problem has persisted on both OS's with no other software or peripherals than what is in the box. I'm at my wit's end on this one. I agree that if it looks ok in safe mode then it is probably a software issue, but I can't find it.
[doublepost=1538942950][/doublepost]

PRAM battery will make no difference. None.

OP:
If safe mode works, I suggest this:
- Create a NEW administrative account in "users & groups".
- this is "for test purposes only", don't add anything to it other than the stuff that Apple puts in there.
- Log into this new test account.
- Are the results same as a safe boot (i.e., "good")? Or are they bad, as your regular account?

If the test account is consistently "good", then, as Richard mentioned above, it's probably something in your regular account (software that you added) that is the source of the problem.
Could most likely be kernel extension (kext), startup item, etc.

One other question:
Have you added RAM to the Mini at some point?

I'll try your suggestion and post back with results. I'm thinking that with a fresh OSX install with nothing other than the standard Apple stuff on there, my personal account is similar to what I will have with a test account. I have upgraded RAM from Apple 4GB tp Crucial 16GB, but it ran fine with this memory before. In safe mode it shows the 16GB in "about my computer". It's probably worth mentioning that I can't log in to my admin account (or any other account) in normal mode, only in safe mode. In normal mode it takes my password then freezes with the dots all over the screen.
[doublepost=1538943074][/doublepost]

[doublepost=1538942013][/doublepost]Hello Miat, thanks for the reply. Yes, I have replaced the battery and it is still doing this.
[doublepost=1538942541][/doublepost]
Hi Richard, thanks for the input. I have done a total wipe and a clean install of High Sierra and then Mohave and the problem has persisted on both OS's with no other software or peripherals than what is in the box. I'm at my wit's end on this one. I agree that if it looks ok in safe mode then it is probably a software issue, but I can't find it.
[doublepost=1538942950][/doublepost]
I'll try your suggestion and post back with results. I'm thinking that with a fresh OSX install with nothing other than the standard Apple stuff on there, my personal account is similar to what I will have with a test account. I have upgraded RAM from Apple 4GB tp Crucial 16GB, but it ran fine with this memory before. In safe mode it shows the 16GB in "about my computer". It's probably worth mentioning that I can't log in to my admin account (or any other account) in normal mode, only in safe mode. In normal mode it takes my password then freezes with the dots all over the screen.

Thanks for taking the time to help, Fishrrman.

 

[WPS408]

PRAM battery will make no difference. None.

OP:
If safe mode works, I suggest this:
- Create a NEW administrative account in "users & groups".
- this is "for test purposes only", don't add anything to it other than the stuff that Apple puts in there.
- Log into this new test account.
- Are the results same as a safe boot (i.e., "good")? Or are they bad, as your regular account?

If the test account is consistently "good", then, as Richard mentioned above, it's probably something in your regular account (software that you added) that is the source of the problem.
Could most likely be kernel extension (kext), startup item, etc.

One other question:
Have you added RAM to the Mini at some point?

Fishrrman, I created a new Admin account in safe mode and then tried to boot normal mode and log in to it. The same thing as my normal user account happened. It just froze after I entered the password with the dots everywhere, spinning beach ball, screen blinks and never goes to the actual desktop. The dots appear after the White apple with the progress bar. After that screen disappears, the screen is black just before the user log in screen appears. This is when the dots show up. The apple with the progress bar screen looks normal.

 

[JoeInMilwaukee]

Try running the extended Apple Hardware Test if you haven't done so already.

Also try going back to the original Apple 4 GB of RAM. Remember that the Intel HD Graphics 4000 shares this RAM with the system.

 

[Richard8655]

Hi WPS408. In addition to the suggestions from Miat, Fishrrman, and Joe (especially trying the original Apple memory), I found this article in AppleToolbox regarding strange Mac behavior due to corrupt user accounts. Both potential solutions are done in safe mode. The reason a corrupt user account is suspected is that the problem occurs at user account log in. Worth a try.

https://appletoolbox.com/2016/07/fi...Hide_and_Seek_Finding_the_Bad_Preference_File

Boot Up Safe Mode
If you don’t have a spare admin account, let’s try rebooting your Mac in Safe Mode. We’ll then remove some of your cache files that may be the source of the problem.

To boot in safe mode, shut down your computer

1. Press the power button
2. After hearing the startup tone, press and hold the Shift key
3. Release when you see the gray Apple icon and the progress bar
4. Once safe mode is loaded, open a Finder window
5. Press Cmd-Shift-G.
6. Type in ~/Library/Caches to go to the caches folder

Totally removing the cache is not recommended so save a backup of all the cache files before deleting them. If something happens, you can restore the old files using the backup.

1. Create a folder in Shared and place the Cache backup there
2. Once you get a backup, go ahead and delete the Cache
3. Restart the computer

Now check and see if this solved the problems with your user account. If not, continue to next steps.

Hide and Seek: Finding the Bad Preference File
This one is deadly boring and time-consuming, but it’s still a better option than having a non-working computer. A corrupt preference file(s) is often the cause for unusual behavior on your Mac, especially if an application isn’t opening or crashes frequently. Preference files store all sorts of application-specific information, everything from your browser’s home page to font settings, and even things like the shortcuts you keep in your Finder sidebar. Let’s first boot up in safe mode. Remember in this case patience really is your biggest ally (and virtue.)

1. Reboot into Safe Mode
2. Open a Finder window and press Cmd-Shift-G
3. Type in ~/Library/Preferences

Move those preference files one by one somewhere else, preferably in a folder marked OLD Preferences. Restart your computer each time and see if the user account is fixed. Yes, I did warn you about the deadly part of this solution.

 

[WPS408]

Try running the extended Apple Hardware Test if you haven't done so already.

Also try going back to the original Apple 4 GB of RAM. Remember that the Intel HD Graphics 4000 shares this RAM with the system.

Hi JoeInMilwaukee, thanks for the feedback!

Running the hardware test is a great idea and I didn't realize that was an option! I tried to run it , but when I press D after the start tone, the screen goes black and does nothing. I do not have a firewall password and, for giggles, I automated my log in password and turned firewall off. Same result when I press D at start up.

I have replaced Ram with the Apple 4GB it came with and it still does the same thing.
[doublepost=1539001185][/doublepost]

Hi WPS408. In addition to the suggestions from Miat, Fishrrman, and Joe (especially trying the original Apple memory), I found this article in AppleToolbox regarding strange Mac behavior due to corrupt user accounts. Both potential solutions are done in safe mode. The reason a corrupt user account is suspected is that the problem occurs at user account log in. Worth a try.

https://appletoolbox.com/2016/07/fi...Hide_and_Seek_Finding_the_Bad_Preference_File

Boot Up Safe Mode
If you don’t have a spare admin account, let’s try rebooting your Mac in Safe Mode. We’ll then remove some of your cache files that may be the source of the problem.

To boot in safe mode, shut down your computer

1. Press the power button
2. After hearing the startup tone, press and hold the Shift key
3. Release when you see the gray Apple icon and the progress bar
4. Once safe mode is loaded, open a Finder window
5. Press Cmd-Shift-G.
6. Type in ~/Library/Caches to go to the caches folder

Totally removing the cache is not recommended so save a backup of all the cache files before deleting them. If something happens, you can restore the old files using the backup.

1. Create a folder in Shared and place the Cache backup there
2. Once you get a backup, go ahead and delete the Cache
3. Restart the computer

Now check and see if this solved the problems with your user account. If not, continue to next steps.

Hide and Seek: Finding the Bad Preference File
This one is deadly boring and time-consuming, but it’s still a better option than having a non-working computer. A corrupt preference file(s) is often the cause for unusual behavior on your Mac, especially if an application isn’t opening or crashes frequently. Preference files store all sorts of application-specific information, everything from your browser’s home page to font settings, and even things like the shortcuts you keep in your Finder sidebar. Let’s first boot up in safe mode. Remember in this case patience really is your biggest ally (and virtue.)

1. Reboot into Safe Mode
2. Open a Finder window and press Cmd-Shift-G
3. Type in ~/Library/Preferences

Move those preference files one by one somewhere else, preferably in a folder marked OLD Preferences. Restart your computer each time and see if the user account is fixed. Yes, I did warn you about the deadly part of this solution.

Hi Richard8655, thanks for the suggestions! I'll try to make time tonight to go through them and I'll post back with results afterwards.

I tried putting the Apple 4GB RAM back in yesterday and it is still doing the same thing.

 

[Fishrrman]

OP wrote:
"I have upgraded RAM from Apple 4GB to Crucial 16GB, but it ran fine with this memory before."

Regardless of "how it ran before", I suggest you put the factory RAM back in and try it that way for at least a week. Does that change anything?

 

[WPS408]

OP wrote:
"I have upgraded RAM from Apple 4GB to Crucial 16GB, but it ran fine with this memory before."

Regardless of "how it ran before", I suggest you put the factory RAM back in and try it that way for at least a week. Does that change anything?

Yes, factory RAM was reinstalled yesterday morning and there is no change.

 

[Fishrrman]

OP wrote:
"Yes, factory RAM was reinstalled yesterday morning and there is no change."

If you're getting errors now even in safe mode, it's almost time to consider "hardware failure".

As others have suggested that there could be software problems even in safe mode, I'd try this first:
1. Use an external drive of some sort (could even be a USB flashdrive of sufficient capacity)
2. Install a completely-fresh copy of the OS onto the external drive.
3. Boot from the external drive and set it up with a simple account.
4. Do you still get the video problems?

One other thought:
Have you tried A DIFFERENT DISPLAY? (you may have already mentioned this)
Or a different connecting cable?

 

[WPS408]

OP wrote:
"Yes, factory RAM was reinstalled yesterday morning and there is no change."

If you're getting errors now even in safe mode, it's almost time to consider "hardware failure".

As others have suggested that there could be software problems even in safe mode, I'd try this first:
1. Use an external drive of some sort (could even be a USB flashdrive of sufficient capacity)
2. Install a completely-fresh copy of the OS onto the external drive.
3. Boot from the external drive and set it up with a simple account.
4. Do you still get the video problems?

One other thought:
Have you tried A DIFFERENT DISPLAY? (you may have already mentioned this)
Or a different connecting cable?

Safe mode is still operating fine. I’m starting to fear a hardware issue, but I’ll try your suggestions as well as Richard 8655’s as soon as I get the chance. I have another Mac mini I have hooked up to the monitor using the same cables and it works fine. I was thinking the same thing. I appreciate all the input Fishrrman, thank you! I’d like to see how the Apple hardware test comes out as Joe recommended, but I can’t get it to run. Just a black screen with no activity. I even disabled my firewall and log in password and it still won’t work. I’m not sure if that has anything to do with what’s going on or not.

 

[Fishrrman]

"Safe mode is still operating fine. I’m starting to fear a hardware issue, but I’ll try your suggestions as well as Richard 8655’s as soon as I get the chance."

If it works in safe mode, it should not be "hardware".
The ONLY THING that changes between safe mode and a "regular boot" is SOFTWARE.
(I could be mistaken, I welcome corrections on this)

Something "in software" is causing this.

Wondering -- have you ever done anything to change the amount of RAM that the system allocates for the display?

 

[WPS408]

"Safe mode is still operating fine. I’m starting to fear a hardware issue, but I’ll try your suggestions as well as Richard 8655’s as soon as I get the chance."

If it works in safe mode, it should not be "hardware".
The ONLY THING that changes between safe mode and a "regular boot" is SOFTWARE.
(I could be mistaken, I welcome corrections on this)

Something "in software" is causing this.

Wondering -- have you ever done anything to change the amount of RAM that the system allocates for the display?

I truly hope it’s a software issue, I’m not the guy to correct anyone though. I know just enough to get me in trouble. Or rather, I know enough to typically keep myself out of trouble. That’s why I have never messed with RAM reallocation. That’s something more advanced that I’ve never needed to do.
I just use my Macs for standard home computing needs and have never needed more out of them than what they have done from the factory. Other than a RAM upgrade because I use Logic Pro X (an Apple music recording app).

 

[Neodym]

How do you connect the monitor? HDMI or TB (DP)? Try the port currently not used in your setup (if possible). Alternatively try to switch to a lower resolution and see if that changes anything.

Regarding safe mode: I would expect that safe mode also relieves certain timings for e.g. Ram, disk or chipset access, even though Apple would probably never confuse it’s customers with such technical details in official support documents

If the affected component is on the edge, it might work with eased settings from safe mode, but fail with the more aggressive timings of standard mode. Perhaps safe mode also defaults to a lower standard resolution (which would lower the pixel clock = less aggressive timing), which could explain it working seemingly normal.

 

[WPS408]

Try running the extended Apple Hardware Test if you haven't done so already.

Also try going back to the original Apple 4 GB of RAM. Remember that the Intel HD Graphics 4000 shares this RAM with the system.

Joe, I got the extended Apple hardware test to work by pressing Option and D at start up to run it from the internet. After running the extended test it came back with no hardware issues. I have also been running the factory 4GB Ram since Sunday morning (10/7/18).
[doublepost=1539089663][/doublepost]

Hi WPS408. In addition to the suggestions from Miat, Fishrrman, and Joe (especially trying the original Apple memory), I found this article in AppleToolbox regarding strange Mac behavior due to corrupt user accounts. Both potential solutions are done in safe mode. The reason a corrupt user account is suspected is that the problem occurs at user account log in. Worth a try.

https://appletoolbox.com/2016/07/fi...Hide_and_Seek_Finding_the_Bad_Preference_File

Boot Up Safe Mode
If you don’t have a spare admin account, let’s try rebooting your Mac in Safe Mode. We’ll then remove some of your cache files that may be the source of the problem.

To boot in safe mode, shut down your computer

1. Press the power button
2. After hearing the startup tone, press and hold the Shift key
3. Release when you see the gray Apple icon and the progress bar
4. Once safe mode is loaded, open a Finder window
5. Press Cmd-Shift-G.
6. Type in ~/Library/Caches to go to the caches folder

Totally removing the cache is not recommended so save a backup of all the cache files before deleting them. If something happens, you can restore the old files using the backup.

1. Create a folder in Shared and place the Cache backup there
2. Once you get a backup, go ahead and delete the Cache
3. Restart the computer

Now check and see if this solved the problems with your user account. If not, continue to next steps.

Hide and Seek: Finding the Bad Preference File
This one is deadly boring and time-consuming, but it’s still a better option than having a non-working computer. A corrupt preference file(s) is often the cause for unusual behavior on your Mac, especially if an application isn’t opening or crashes frequently. Preference files store all sorts of application-specific information, everything from your browser’s home page to font settings, and even things like the shortcuts you keep in your Finder sidebar. Let’s first boot up in safe mode. Remember in this case patience really is your biggest ally (and virtue.)

1. Reboot into Safe Mode
2. Open a Finder window and press Cmd-Shift-G
3. Type in ~/Library/Preferences

Move those preference files one by one somewhere else, preferably in a folder marked OLD Preferences. Restart your computer each time and see if the user account is fixed. Yes, I did warn you about the deadly part of this solution.

Richard8655, I tried your recommendations from AppleToolBox last night (10/8/18) and it still has the dots at start up and freezes after I enter in my password. Thanks for the suggestions, they were good ideas! I may try to erase the hard drive and install OSX 10.14 again just to say I did.
[doublepost=1539090778][/doublepost]

How do you connect the monitor? HDMI or TB (DP)? Try the port currently not used in your setup (if possible). Alternatively try to switch to a lower resolution and see if that changes anything.

Regarding safe mode: I would expect that safe mode also relieves certain timings for e.g. Ram, disk or chipset access, even though Apple would probably never confuse it’s customers with such technical details in official support documents

If the affected component is on the edge, it might work with eased settings from safe mode, but fail with the more aggressive timings of standard mode. Perhaps safe mode also defaults to a lower standard resolution (which would lower the pixel clock = less aggressive timing), which could explain it working seemingly normal.

That's a good idea, thanks Neodym! I have it connected HDMI right now, I'll see if there is an alternate way of connecting it. It's a pretty no frills monitor, so I may have to get an adapter. So, if it works with the resolution decreased or on a different port, what does that tell me? That I either have a GPU or HDMI port issue (or basically my logic board is failing)? Sorry for the newb question, but this is outside of my normal troubleshooting. I switched to Mac in 2011 and I have never had an issue anywhere near this scale.

 

[Richard8655]

One more thought WPS408, if still not working. I’d take the Mini to a local Apple Store and have the Genius Bar take a look. They have all kinds of software and hardware diagnostic tools not generally available to customers. I took my late 2012 2.3 I7 (exact model as yours) to them with an OS install problem, which they resolved at no charge.

 

[Neodym]

So, if it works with the resolution decreased or on a different port, what does that tell me? That I either have a GPU or HDMI port issue (or basically my logic board is failing)?

Those are possible scenarios, indeed. Could also be as simple as accumulated dust (a can of compressed air can help wonders inside - but only after the mini has cooled completely and taken off power) or the heat transfer paste having grown old, thus offering reduced temperature transmission capabilities.

Perhaps you can check the activity monitor for unexpectedly high activities and get some temperature monitor software (such as e.g. iStat Menus or MacsFanControl) to read the current temps and fan rpm (another possible scenario: fan broken).

Difficult to tell remotely, thus the suggestion to go see an Apple genius might be a good idea, if the other tests and fan/temp monitoring don’t show any unusual conditions.