mac mini doesn't turn on

[geppetto]

I (actually my son's) have a mid 2011 mac mini that doesn't turn on. Symptoms - fan spins for a split second, sleep indicator light turns on and then off, no sound..that's it. I tore it down, removed the power supply and tested it. It was putting out 12 volts on 4 of the wires per a schematic I found online. I removed the hard drive and found it had errors so I back up the data and reformatted it. I put it all back together and get the same symptoms. When I tested it I did not plug in the keyboard nor a display monitor.
1. Is it necessary to have the keyboard and display plugged in to start the power on sequence?
2. Does this sound like a logic board failure? If so, suggestions on what might be the culprit?

Thanks for your help!

 

[Trusteft]

How many monitors u have connected to it?

 

[wlossw]

I (actually my son's) have a mid 2011 mac mini that doesn't turn on. Symptoms - fan spins for a split second, sleep indicator light turns on and then off, no sound..that's it. I tore it down, removed the power supply and tested it. It was putting out 12 volts on 4 of the wires per a schematic I found online. I removed the hard drive and found it had errors so I back up the data and reformatted it. I put it all back together and get the same symptoms. When I tested it I did not plug in the keyboard nor a display monitor.
1. Is it necessary to have the keyboard and display plugged in to start the power on sequence?
2. Does this sound like a logic board failure? If so, suggestions on what might be the culprit?

Thanks for your help!

Connecting a display and I put device will help your troubleshooting.

 

[geppetto]

How many monitors u have connected to it?

My son had 1 monitor connected to it when it wouldn't power on. Then he brought it to me. I didn't connect any monitors to it when I was testing - I just wanted to see if it would beep or the fan would spin or something. I figured it would go through some power on testing and give some beeps indicating a problem but it doesn't do anything but 1 flash of the sleep indicator light and a slight spin of the fan.

 

[Trusteft]

Have you tried hard reset? After it fails to boot, hold the power button for 5+ seconds. Wait and if nothing happens (it shouldn't), switch it on again.

 

[geppetto]

I connected up the keyboard and a monitor. Held power button for 5 seconds or even longer. No difference. SIL blinks once and fan spins for a a fraction of a second. No sound, nothing on the display. I had checked the voltage on the battery and it's 2.93 volts. Any other suggestions?

 

[Sandman77]

Could be dodgy RAM. If you have 2 sticks of RAM in the machine can you remove one then test it and if it still doesn't work try again with the other stick.

 

[Trusteft]

Could be dodgy RAM. If you have 2 sticks of RAM in the machine can you remove one then test it and if it still doesn't work try again with the other stick.

Also on different slot.

 

[geppetto]

I tried swapping the RAM - same results.

 

[DeltaMac]

Try disconnecting the internal hard drive.
If the power will stay on, then replace the hard drive.
If no change, then most likely the power supply has failed (won't maintain power under load)

 

[geppetto]

I'll give that a try, but I've already taken the hard drive out of it and copied any files over to another drive. I reformatted the drive and it seems to be ok. Also, the power supply was putting out 12 volts on the four leads that I found in a schematic.

 

[belvdr]

Also, the power supply was putting out 12 volts on the four leads that I found in a schematic.

Voltage is one thing; amperage is another. If the current exceeds what the power supply can provide, it won't work.

 

[geppetto]

I disconnected the hard drive. Same results. I disconnected the fan - just the SIL blinks 1 time each time power is pressed. Memory removed, same - SIL blinks 1 time. And through all of this, no sound at all.

 

[RyanXM]

This is a GPU related issue. I have 11 (yes, 11) of these sitting next to me with the same system. I have tried a Known Good power supply and the issue persists. I have gotten a few of them to work by "baking" the logic board. They will work for a few days and then no longer turn on.

There is a place in NYC that will do a component level (capacitor, timing clock, BIOS chip, etc) repair for $150. I've used them on a few 2012 models and they are still running to this day.