My 2012 Mac Mini is no longer starting up. I've got a multimeter but very little experience using them. I've ruled out the power cable, so I assume either my power supply or my logic board has died, and I'd like to figure out which it is. Can anyone give me any guidance how a layperson would use a multimeter to determine if the power supply is the culprit?
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How do I test a Mac Mini's power supply with a multimeter?
- Thread starter whartung
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A quick Internet search using the parameters "mac mini 2012 power supply test" results in this page:
www.ifixit.com
which was the #4 result at DuckDuckGo.
Unsurprisingly, you should check for a +12V on several wires.
This would be the same process as a Windows PC's power supply.
In fact, my Seasonic Focus 650 shipped with a special motherboard cable terminator that shorts out two pins (presumably one of the +12V lines and GND) which makes the PSU believe it is plugged into the motherboard which results in the fan spinning up.
SOLVED: Complete Dead - How To Check Power Supply Vs Logic Board - Mac Mini Late 2012
@mopac01of course you already double checked your outlet and power cord to make sure both are working. Use your multimeter and check for 12V on the wires as described If yours is different, post some images of what your connector looks like etc. Adding images to an existing question - Mac Mini...
www.ifixit.com
which was the #4 result at DuckDuckGo.
Unsurprisingly, you should check for a +12V on several wires.
This would be the same process as a Windows PC's power supply.
In fact, my Seasonic Focus 650 shipped with a special motherboard cable terminator that shorts out two pins (presumably one of the +12V lines and GND) which makes the PSU believe it is plugged into the motherboard which results in the fan spinning up.
Yeah I saw that thread already. Not quite positive what it means I should do in terms of a multimeter though, since I'm pretty unfamiliar with them. Am I plugging the power supply into the wall and then checking for voltage on each of those 9 pins in the bottom of the picture, or am I not plugging the power supply in and instead checking if some pairs of two of those pins pass current across them? I can probably dig something generic up about using multimeters on PSUs on YouTube, just wanted to see if anyone had any specific advice for checking these particular PSUs/Mac Mini logicboards.
Basically yes. When testing wall power, I just switch the multimeter to AC mode then stick the leads into the two vertical slots (hot and neutral). The meter shows whether or not it is delivering around 120V AC.
Same with testing a battery. It switch to DC mode, touch the leads to the battery terminals and see if the meter shows a voltage that the battery is supposed to be providing (1.5V, 9V, etc.).
At least the one I have is a pretty simple device that dates from the mid-Nineties.
Same with testing a battery. It switch to DC mode, touch the leads to the battery terminals and see if the meter shows a voltage that the battery is supposed to be providing (1.5V, 9V, etc.).
At least the one I have is a pretty simple device that dates from the mid-Nineties.
The first suggestion is, since you don't know that voltage has to be measured when power is applied to the circuit (or how it is measured), that you also need, first and foremost, lessons in electricity/electronics safety - both personal safety, and working on the equipment without damaging it.
Skipping the basics is a shortcut to a short circuit. I'm also guessing you're too young to be familiar with this, but back when televisions and computers had CRTs there was a pretty regular occurrence of fatal accidents where untrained tinkerer met high voltage. Today's voltages and currents tend to be much lower so fatal accidents are fewer and farther between, but the electronics is far more susceptible to damage due to electrostatic discharge.
Skipping the basics is a shortcut to a short circuit. I'm also guessing you're too young to be familiar with this, but back when televisions and computers had CRTs there was a pretty regular occurrence of fatal accidents where untrained tinkerer met high voltage. Today's voltages and currents tend to be much lower so fatal accidents are fewer and farther between, but the electronics is far more susceptible to damage due to electrostatic discharge.
To replace the power supply you must completely disassemble the mini. Likewise to get to those pins pictured in the link above to test the voltage . Here is a link to the ifixit guide to replace the power supply.
www.ifixit.com
How to use a voltmeter is like step 23 of the process. You will probably need to buy the toolkit to get the logic board removal tool. Are you sure you want to do this yourself?
Mac mini Late 2012 Power Supply Replacement
Use this guide to replace a faulty power supply.
www.ifixit.com
How to use a voltmeter is like step 23 of the process. You will probably need to buy the toolkit to get the logic board removal tool. Are you sure you want to do this yourself?
To replace the power supply you must completely disassemble the mini. Likewise to get to those pins pictured in the link above to test the voltage . Here is a link to the ifixit guide to replace the power supply.
Mac mini Late 2012 Power Supply Replacement
Use this guide to replace a faulty power supply.
How to use a voltmeter is like step 23 of the process. You will probably need to buy the toolkit to get the logic board removal tool. Are you sure you want to do this yourself?
Yeah, I've already got all the tools to tear down Mac Mini, and already took it apart and figured out how to test the power supply actually.
Got nearly 12v on every one of the pins when the PSU was plugged into an outlet. So I suppose that suggests the PSU isn't the culprit?
Which unfortunately means the logicboard is probably dead, I guess. Only other option would be the power button itself, but that was seated properly and the computer turned off on its own, not me shutting it down, which I assume means it is less likely to have to do with the power button.
sorry to revive an old thread... I am having a similar issue with my Mac Mini, it does not power at all after a storm event. I am reading 25V in the positive pins, does this mean my power supply is the culprit?
Thanks in advance!
Thanks in advance!
Thanks for the constructive input... the post was not mine originally. I'm having a similar issue, but I'm reading 25V in the positive pins and would like to have feedback
Ooops.
I skimmed while I’m on a lunch break. Didn’t realise this was an old post.
Now I look a little silly
Is that defo 25V? not 2.5? There are supposed to be some signal wire-s that do 2.5, the mains are 12v, nothing in there should do more than that.
Not sure on the configuration of the Mac Mini power supply but is AC correct for that part of the circuit?
True, my mistake... in DC voltage it reads 11.8V. So power supply is probably good?
Having nothing to do with the power supply... A multimeter with sockets for testing discrete transistors (that's that grid of small holes right below the display). When's the last time they made one of those?
NPN, PNP, EBCE (Emitter, Base, Collector, Emitter)... ah, the good old days!
NPN, PNP, EBCE (Emitter, Base, Collector, Emitter)... ah, the good old days!
Well, that's unfortunate... I was hoping it was the PSU, because the alternative is the logic board.
Hi there! I just got the same problem here.
I was connecting a external drive to one of the usb ports the suddenly it shut down with a "pop" sound.
My power supply also reads 11.95v on the multimeter. So I guess it's the mboard that burned out?!
I was searching for a new one but the prices are too high. I seems that it´s better to buy a used mac mini than a new or used mboard. What do you guys think?
Thanx