Released June 2012, Model A1278. Intel processor with Turbo Boost, Up to 512 MB DDR5 Video RAM

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Issues with bottom RAM-slot MBP 2012

Hi guys,

I bought a used MPB 13'' Mid 2012 this week.

I got the system with 1 4GB RAM stick installed (in the top-slot) and the other slot being empty.

I bought myself 2x 8GB of RAM (Corsair Vengeance 1600Mhz DDR-3)

After putting in both sticks the macbook didn't start. No beeps, black screen, just 3 flashing/blinking lights at the LED indicator, with a 1 second pause in between the 3 flashes.

Put the old RAM back in the bottom slot, same problem.

Put the 8GB RAM back in the top slot, system boots normally with 8GB of RAM.

Pretty much tried everything after that, SMC reset, PRAM reset, loosening screws of RAM-bracket.

After that I tried to put 1 RAM stick back in the bottom slot, and tried to boot.

This time it booted, with black stripes flashing in the screen and the boot taking a very long time while the load bar was not progressing (hope this makes sense to read).

So I turned the system off, put the 8GB stick in the top slot and now working fine with 1 8GB slot.

Really would like the bottom slot to work as well, feels like i am out of options.

(Not going to replace the logic board for this problem)

Can anyone help, or has anyone had the same problems?

Thanks in advance!

Answered! View the answer I have this problem too

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I have the same problem. It's some kind of bad contact problem with the bottom RAM-slot and I don't know how to fix it.

@nawo13 did you find a solution on your problem?

I have a mid 2012 MacBook Pro.




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Sounds like you have either the wrong RAM module (spec) or the systems firmware is not up to date (I would be surprised if it's not already at the correct level).

With the 4 GB module in place with the system working lets first try checking the firmware. Follow this Apple T/N: About EFI and SMC firmware updates for Intel-based Mac computers. Make sure its at the listed level or newer.

If the firmware is OK, give us the part number of the Corsair you ordered and take a good image of the labels on one of the modules as well as the memory chips so we can read them and post them here as an answer.

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Thanks for the reply.

Firmware is up to date (as expected)

RAM-module is Corsair Vengeance 16GB (2x8GB) 1600MHz DDR3

System (MBP Mid 2012) needs 1600MHz DDR3 RAM.

I think the problem is not the module, also tested it with the old RAM (that worked fine in the top slot) and tested it with Crucial Apple RAM 4GB (that worked fine in top slot and failed in bottom slot)


Then the RAM slot is bad. Jump down to Mayers solution as thats your only hope. Otherwise you'll need a new logic board.


before you change the logic board you can try some distance holders between ram bracket holder and top case ... the ram slot can be good, but the ram bracket holder looses contact to the mainboard. I had exactly the same issue.


It doesn't sound like that, Dan.


pearsaml - Explain more fully...


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Most Helpful Answer

Mayer 's tip is really good. At this model the RAM bracket holder often looses contact with the bottom side on the logic board (side you can not inspect without dismounting the mainboard). This leads to freezes, reboots, stripes and display errors.

ReSoldering the bottom side of the RAM bracket holder is quite a challenge and often you will get an offer to replace the whole mainboard (>400 USD !!!).

Option 1: you can use only one slot (the top one usually).

Option 2:

If you want to use both slots (instead of only one - either top or bottom) , you can try to put some distance holder between RAM bracket holder and top case. I solved once a time this problem with a short stripe of an old credit card. Put it between the RAM bracket holder and top case. This will "press" the RAM bracket holder to the mainboard or in other words, if you shake your Mac book pro or just type on the keyboard, the RAM bracket holder will not loose contact and the problem is fixed (yes with a workaround (0 USD :-) )

give it a try :-)

here a picture of the first tests. With this place holders no freeze, no reboot, ... :

Block Image

as said: it is a quick fix and take care to find the right distance - do no damage your logic board.

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This did not help with a MBP with bottom ram slot issues I bought off Ebay. It's getting returned to the jerk who sold it!


Tried didn't work for me. You placed the contacts (plastic strips) pushing up underneath the RAM bracket as well right?


Yes, I put the strips underneath the ram slot bracket to push up, and strips on the top to push down off the back case (just as in the picture). The laptop had been dropped and the solder joints on the bottom slot are different (inferior) than the top slot, there's really no hope if this method doesn't work. It is a good idea though, just didn't work for that laptop. I don't know what had been subjected to, but, I was able to get my $ back. I should add, this method did make it a little more stable, but once the laptop was moved, it would often crash. The lower ram slot did hold the ram stick firmly, so I don't think the styrene ball trick would have worked.


Thank you very much for this idea, I have not seen this anywhere else in my search for fixing the bottom ram slot. I guess I got lucky because this completely fixed my laptops freezing and beeping without sacrificing half my ram.

Thanks again Gludie!


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Hey everyone, after having this problem, i found out the problem might not be the soldering at all. read on...

I have a MBP 15" early 2011, had the logic board replaced in the apple program for the video chip, after that, i started to get kernel errors once in a while, all was pointing to RAM, but could never actually find a defective stick and tried many, after a while of seating and reseating the sticks and a fresh install os the macOs it stopped for almost a year with no problems i thought i was done; only to begin crashing, powering off and beeping this week.

i've been reading forums about this problem and after watching this video

I'm having exactly the same problem as this.

So I took it apart again, and what did i find... apparently, as i said, and for everyones happines it migh not be the soldering at all!!

It seem the CLIPS that hold the stick closest to the keyboard are worn and do not have enough pressure so they do not hold the ram in place all the time, a little bump and the RAM stick springs up like half a milimeter and the problem appears.

What did i do? Got a 1.5mm (.60 cal) piece of flat styrene about 3mm wide and 7 or 8 mm tall, put BOTH RAM sticks in place and with a little plastic tip/spudger push down the stick closest to the keyboard so the clip can make its full travel inward and insert the styrene pieces one in each side in the slots between the clip and where the screws for the bracket are and then push them towards the RAM contacts to make pressure inward so the clips are pressed firmly against the sticks (you wont be able to remove the sticks without removing this styrene pieces).

Block Image

I did this, the MBP started with no problems, i can now shake it and won't freeze and/or beep at all.

I'll try to make a video or at least a photo guide showing what i mean and post the link (it will be my first YT video so be nice hahaha) so it shows the fault and fix clearly.

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Hi :) any update on the YouTube video or the photo guide?


Part 1/2

The santiagogdelatorre solution, above, worked for me like a charm. Thank you Sir.

2012 MacBook Pro (non-Retina 13-inch 9,2 MD101LL/A)


Symptoms shown in these videos, which would occur within seconds of powering on the machine.

The symptoms occurred whenever I had a RAM card in the rear slot. No symptoms occurred with only a single RAM card in the front slot (empty rear slot).


Running continuously with normal use for 4 days with both RAM slots filled, zero issues so far.


RAM Configuration


I found during testing:

1. This machine will run with EITHER a single RAM slot filled, or both slots filled.

2. When using both slots, the size of the RAM cards can be DIFFERENT. For example, I'm now running 10GB RAM = 2GB in rear slot + 8GB in front slot.

3. This machine supports up to 16GB RAM. The RAM must be 1600MHz DDR3.


Part 2/2

Implementing the Fix


As shown in the red circle in santiagogdelatorre's photo (above), there is a narrow air gap between the the clips which secure the RAM cards in their slots, and the logic board which surrounds the RAM cards. Purpose of the fix is to fill this gap, thus securing the clips in place.

I used strips of old credit cards as "filler" to insert into the gaps. I layered 2 old credit cards of different thicknesses to fit into the gap. The correct "snugness of fit" is that the strips don't fall out by gravity if you flip over the machine, but you can easily pull them out with a tweezer. To make fillers of the correct size, I cut the credit cards into ~1" x .25" strips that fit into the gaps and, with both RAM cards in place, I inserted the strips into the gaps. Then I marked the correct "depth" of the strips with a sharpie, and trimmed the top off leaving 1/16" protruding, to remove them with a tweezer if needed. This fits inside the cover of the machine, no problem.


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Sounds like the original owner had the same issue. After you do what Dan says, if it is still doing it.

Try this: We've had reports that loosening the RAM bracket holder screws a quarter turn each has worked.

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Tried and didn't work.


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Solved! Had all the same problems. The display would be covered with checkerboard test patterns or the computer would beep on boot indicating bad memory. Other times it would boot fine, then freeze up. I even found that if it did boot without beeping and displayed a normal screen, if I squeezed the left front of the bottom case just to the left of the track pad, the screen would show the same test pattern blocks and then hang.

So I followed what was tried above and found that by folding up a 3x3 sticky pad and trimming it to the proper width (same as the memory mod.) I was able to press it between the back edge of the bottom memory module thus forcing it forward into the memory slot. Now my machine boots every time with no beep, no more artifacts on the display and I can squeeze it as hard as I can without duplicating the previous display issues.

It all comes down to a weakened bottom memory module retention clip. By pressing something, anything non-conductive at the back of the simm module to keep it pressed forward in the slot all is good again.

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I used this technique and it is currently working, ... Thanks for all the guidance,

I folded a post-it three times and slide it behind the lower module pushing it forward, I then added the upper module sliding it past the paper, both modules are now a little tighter into the slots, ... I will pay close attention to temperature and look around for other non-conductive materials, ... a touch worried about the paper burning,


I substituted the folded post it with the same concept spacer but made from layered heat resistant, non-conductive electrician's tape ... This fix is still working for me,


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I had the same issue with my Macbook Pro mid-2012 13-inch. The symptoms would gradually progress like this:

  • after taking laptop out of my, it would be frozen (black screen, breathing light stuck to 'on')
  • when picking up the laptop while open, screen would display those horizontal stripes / blocks
  • shortly after that, it would progress to the three-beeps situation and not being able to find the RAM
  • there were side effects, like a confused Wifi and MS Outlook crashing its identity, but those were symptoms not causes

After taking it to the repair folks, it would often work without problems again for a long time, even though they had no clue what the cause was. Strangely, taking the RAM sticks out and plugging them back in was not always effective. Or not for long. But sometimes it was.

I was so happy to read Santiagodelatorre's analysis. *That* finally made sense to me. And his solution seems to work for me too.

At the end of the RAM clips, there are little round protrusions that fit in a round opening in the side of the RAM stick. But those are not actually what holds the RAM sticks in place. You need to look even more closely for small plastic 'wings' that extend from those round protrusions.

Photos in a public Google photos album.

(Note on the photos: there are two photos that are almost similar. Except in one, the RAM stick is being held down below the plastic wing, whereas in the other, that's not quite the case. Hard to see, but very real)

Those wings (same material, same color as the rest of the clips) are meant to be flat at the bottom. So that the RAM stick rests against them: flat surface to flat surface.

As you can see in the photos, these wings have become degraded: they're not smooth like the rest of the plastic parts of the RAM clips. It almost looks like the plastic is just falling apart by itself. It doesn't look like wear and tear. Perhaps the sticks get too hot for the plastic.

In my case the protrusion on one side was no longer perfectly flat at the bottom. This was the wing for the bottom RAM stick. Since the RAM sticks are actively pushed upwards and the wing wasn't quite on top of the RAM stick, the stick would gradually push the clip aside, and thus the stick would move upward just a little.

Presumably that causes the memory problem.

This is why shocks (like the laptop receives when I put my bag down) would cause the problem to start. And why the problems gradually got worse. And why there are moments, near the end of that cycle, where the laptop will work fine while flat on a surface, but will crash as soon as I gently tilt it away from me.

I solved the problem similarly to Santiagodelatorre, except with a bigger segment of cut-up credit card, and only on one side.

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Had the same problem with a 2012 13" MacBook Pro. Bottom slot has a bad connection to the logic board. With both RAM slots, in use the symptoms are as follows: displays stripes on LCD, freezing, reboots often, 3 beeps, etc. The computer will work fine if only the top memory slot is used. The only other solution is a logic board replacement.

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I had this same issue happen with my mid 2012 macbook pro a1286. The issue turned out to be the apple serial number sticker on top of the ram slot bracket. For whatever reason, this is a layered sticker with foil, and I guess that the sticker had maybe shifted or degraded slightly with time and heat and shorted the ram contacts. I ended up removing the sticker entirely, laying down some heat resistant Kapton tape in its place, and putting the serial number sticker back on top of that to be sure there was no chance of the sticker shorting the contacts again. Problem solved.

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Nawo13 will be eternally grateful.
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