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Announced on October 16, 2014, identifiable by the model number A1347 and EMC 2840.

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Mac Mini Led blinks but wont boot, no chime.

Hello guys, I´ve received an mac mini late 2014 A1347 for repair and it wont turn on.

Specs are Dual Core i5 2,5Ghz, 8Gb RAM, 1Tb HD.

After I openned it up, I see that the cooler tries to spin but then it stops, checked the power supply from the machine and its giving 12v as it should be, on power supply after I press the power button it goes to 0,4A then zero, then 0,7A then zero again, and it repeats over and over again...

HD is Ok, I can boot from it using another mac, Power Supply is Ok, buttons, flats, I´ve already rehoted the RAMs chips that are soldered to the board just to make shure (theres no beep indicating RAM problem...)

I dont know what else can it be, anyone can help me with an scheme or an more advanced tech tip?

Thanks!

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Are you looking for component level repair advice on this one? is that something you are able to carry out?

In my experience, the mac mini's are as basic as they come when it comes to the hardware functions, as everything is integrated into the logic board.

In diagnosing, we typically start by disconnecting all non-essential components and booting it as basic as possible.

Its very common for the IR cable, or the PWR button to get damaged if it has been previously worked on, so i always start by inspecting those sockets (a short can cause it to not boot)

I also locate the power pads on the logic board to power it on if the power cable is damaged.

Coincidentally, we had a batch of 10 2011 mac minis come in from a client that had suffered from a power surge, and all of them had blown logics. (symptoms were a slight fan twitch, no other response)

But if your LED is flashing in a sequence, see how many flashes it is, as it will be indicating a fault.

i.e. 3 flashes is ram

We've not had the boards faults traced yet, but it will more than likely be a component failure on the board, as a replacement test logic fully worked with the rest of the hardware.

I hope this helps.

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Yes, thats exactly what I was hopping, a component level reair advice. I think that this is the same case with this mini, a power surge caused an component damage that is preventing it from turning on. Unfortunately I returned it to the costumer as as "nofix", since I don't have other macbooks or mini donor boards to pick up other components... But thanks for taking time to answer!

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i have the exact same issue with same hardware, still googling arround

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Hi Jon, were you able to fix? I've got four 2011 i7 mac minis all exhibiting the same behaviour. Fan twitch, white light flashes for a second and no power. I know the Radeon 6630m gpu was an issue with this model but don't think that is the issue with these. Thanks

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Unfortunately, we never got round to having the time to trace the logic board issues. At the time, we didn't have the board schematics to do it, so we just replaced the logic boards and refurbished them all.

But there was a definite power rail issue from the surge on the logic board

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Jon, by power rail issue, do you mean the internal power supply? Would replacing it fix the issue?

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- Try resetting the SMC and NVRAM/PRAM

Intel-based Macs: Resetting the System Management Controller (SMC)

https://support.apple.com/en-us/HT201295

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Sorry, but its more like an hardware issue. I've did all the testings software wise, I'm not a noob in those things, thanks for the tip but a hardware advice would be more than welcome

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Sorry if this is obvious but I had the same issue and then realised that I hadn’t put the RAM back in properly. Had to really push it in hard (so almost none of the connections were showing at all), put it back together and it worked fine.

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I have pretty much the same problem with an A1347 mid-2011 Mini.

Hit power, a flash of light, then nothing.

Power supply, or logic board?

It worked perfectly before it spent two months on a ship (well packed) on it’s way to me here in the UK.

Any pointers on how to isolate the snag would be much appreciated.

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Will need component level repair.... HD6630 goes bad on those boards. Throw some heat at it to see if that helps. Also, I once had a lot of about 5 of those units with bad tantalum capacitors. Replaced and got them all up and running again.

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