Saltar al contenido principal

Repara tus cosas

Derecho a reparar


Lanzado en junio de 2012, modelo A1278. Procesador Intel con Turbo Boost, hasta 512 MB de RAM de video DDR5

Preguntas 1603 Ver todo

Sudden restart loop then black screen


Yesterday I was using my MacBook just fine, connected to the power, when it suddenly restarted: I was in Bootcamp and initially thought it was a Windows 10 issue, but then the Mac partition wouldn't boot and kept restarting; at one point it got stuck on a boot chime loop which wouldn't go past a white screen, then nothing. Now it's stuck on a black screen, no chime, fixed white power sleep light.

My situation:

  • Two SSDs with one replacing the optical drive slot
  • Non Apple RAM upgrade by Crucial replaced in 2016
  • Non Apple battery replaced about a year or so ago
  • Original power cord cable, never replaced

What I tried to figure out the problem:

  • The usual key combinations to reset NVRAM (useless since it won't get to the chime sound part) and SMC
  • I removed my SSDs (white screen with ? symbol), I also checked them with another computer and they're fine
  • I removed the Windows SSD and put the optical drive back in to see if I could hear it start, and it does start
  • I disconnected the iSight camera
  • I reseated the RAM, tried to boot with only one in, then switched
  • I removed the RAM and the Mac obviously didn't start without that, but it beeped and I read somewhere on here that's probably a good thing?
  • I tried booting holding down the Eject key, the Shift key, D/option+D, Cmd+R, etc. and the only thing I noticed is that the sleep light blinked for a few seconds then stayed fixed again
  • I put the original Apple RAM back in and if the Mac is connected to the power and has the battery disconnected, once every 20 to 30 tries the computer goes to a white screen and then actually boots. It stays on for a while, then suddenly turns off for no apparent reason. However, I only managed to make this happen twice in about 6 or so hours, so I'm not sure it's a viable conclusion…
  • If I just try to turn it on, the power sleep light blinks 5 times then stays stuck on white.

Now, what could be the issue that makes this all possible? I never had any kind of hardware problems with this computer so I'm really confused and kinda hoping it's not a logic board failure.

How can I know for certain whether it's that or a RAM issue? Considering even the original RAM isn't spared from the black screen (though it does turn on with that after numerous tries)? Would a logic board failure still make the Mac occasionally boot and work?

I really hope someone here can shed some light on my situation. I care a lot about this computer and would like to see it working again. Thank you for your time.

UPDATE 16/03/2021: Replacing the logic board fixed the problem.

Contestado! Ver respuesta Yo también tengo este problema

Es esta una buena pregunta?

Puntuación 0
Agregar un comentario

1 Respuesta

Solución Elegida

Sounds like you want the problem to be anything but what it truly is! Your logic board has bit the dust!

Here’s the guide to replace it MacBook Pro 13" Unibody Mid 2012 Logic Board Replacement


Fue útil esta respuesta?

Puntuación 1


LOL I was hoping for it to be anything else... Thanks for answering though. Do you know if I need to replace it with an exact same one or not? I've been browsing online and mine (820-2565-A) is not so easily found... I've found tons of 820-3115-B models though.

- de

Here's one source: Mid-2012 13" MacBook Pro Unibody Logic boards These are the only alternative boards your system could support Early/Late 2011 13" MacBook Pro Unibody Logic boards

The 2011 boards CPU internal graphics engine is not as good when pressed hard doing any heavy graphics. I would stick with the 2012 board which has an Intel HD Graphics 4000 engine over the 2011's Intel HD Graphics 3000 engine.

- de

The MBP 13" 2012 use the 820-3115 board, the 2011 use the 820-2936 so I guess you have the 2010 model. 2011-2012 boards won't fit in the 2010 case.

- de

@redflag @lemerise - Double check your system! If Lemeise is correct then you need to use the 2010 board as the 2011 or 2012 won't work!

- de

Well, I replaced the logic board and it works perfectly now. I guess I just couldn't believe the old thing would give up on me, at first! Thank you all for answering; Dan, I will print out your answer and give it a special place in my room lol. I needed that metaphorical kick in the butt to finally buy a new logic board. I was unsure because of the price, but I love this Mac to death and if I can give it a few more years of life I'll gladly do so. Thanks again.

P.s.: Last time I looked at the model number printed near the AC connector, but the true serial code for the logic board was 820-3115-B, printed on the logic board itself. So all the boards I was seeing online were actually compatible.

- de

Agregar un comentario

Añadir tu respuesta

Red Flag estará eternamente agradecido.
Ver Estadísticas:

Ultimas 24 horas: 0

Ultimos 7 días: 0

Ultimos 30 días: 4

Todo El Tiempo: 64