Diagnosing Mini 2012 power supply

[sfphoto]

2012 Mini sometimes will not wake from sleep, sometimes takes several minute to boot and other issues that would seem related to the power supply.
I doubt the Genius Bar would even run their diagnostics due to age. Plus when I took them a 2015 MBP w/ non-working camera their diagnostic showed the camera was fine (even thoughPhotoBooth etc. said no camera connected). They kept the machine overnight and then admitted they were perplexed.

Knowing the value of the Mini I suspect it should become spare parts. Have not tried 'Option+D' start as have read it really does not test power supplies.
Any comments?

Thanks in advance~

 

[Kenny99]

Your description of your problem indicates a “Wake From Sleep” issue. Have you looked (searched) for possible solutions for this?

 

[meson]

Given your description, I would look closely at the cable that connects the drive to the logic board. My 2012 MBP would do similar things when the ribbon cable that connected the drive to the logic board was failing. Then one day it would display a circle with a slash through it indicating that no drive could be found when the cable finally failed. It was a known issue on laptops, and I went through 3 cables between 2013 and 2018. I don't recall reading about this type of issue in the mini, but it's one of the first places I'd look, and should be a cheap fix.

Also given the age of the machine, I would be concerned for the health of the drive if it has not been replaced recently. A SATA-based SSD was a huge upgrade for machines of that era.

 

[dazey]

doesnt sound like a PSU issue to me, other suggestions sound sensible. I would expect PSU faliure to be more likely to result in completly dead unit, or one that falls over on high load. Its only DC cabling between the PSU and the motherboard on the mini, so there are no genius bar tools to test it.

 

[weckart]

My first 2012 Mini was similar. Sometimes it wouldn't boot up at all and the only fix was to leave it for a few hours with the cord detached. Then it usually played ball but sometimes it would need a couple of breaks before posting. I thought it was the psu at first, so shelled out for another but that did nothing. So we are looking at the power rails on the logic board and failing capacitors. At this stage, it's quicker and cheaper to get another Mini, which I did.

 

[Fishrrman]

OP wrote:
"2012 Mini sometimes will not wake from sleep, sometimes takes several minute to boot and other issues that would seem related to the power supply."

I have both the 2012 Mini, which was later replaced by the 2018 Mini.

Something I've noticed about both of them:
Occasionally they can become balky when either starting up or waking from sleep.

My take on this is that there's been a "loss of proper synching or communications" between the Mini and the display. Trying to get com "re-established" may be difficult, with the only solution being a reboot. Sometimes you can unplug and re-connect the display cable, but even this may not work.

I've found something that helps.
I offer this not as "a solution", but rather a work-around that often helps.

a. Power down, all the way off
b. Put your finger on the option key and keep holding it down as you press and release the power on button.
c. Don't let go of the option key.

What you're doing is invoking the startup manager.
For some reason, doing this will "liven up" the display, even if it had been giving you trouble a few moments earlier.

It doesn't matter if you have only one startup disk, and that it's "already chosen" in startup manager.

Just let startup manager display the (only) boot drive, hit the enter key, and let things continue.

My prediction is that you'll get "a proper boot" in most cases.

Again, not a solution -- but I find this works for me.

 

[sfphoto]

Thanks for all the comments!

 

[chrfr]

After this long I'd probably start by changing out the battery on the logic board. It's a cheap and easy thing to test. If you do this, make sure you get a less-common BR2032 rather than a CR2032.

 

[sfphoto]

OP wrote:
"2012 Mini sometimes will not wake from sleep, sometimes takes several minute to boot and other issues that would seem related to the power supply."

My take on this is that there's been a "loss of proper synching or communications" between the Mini and the display.

So I have done two things.
Run Disk Warrior while the Mini was running from an external (numerous errors fixed).
Freed up disk space.
Now connected to a different display. Has only been a couple of day but all seems fine.

Thanks Fishrrman et al

PS - battery seems pretty deep inside the machine so not eager to tackle such