Stuck on Fans turning/no chime when trying to boot
Hey everyone,
I've recently got an Macbook Pro late 2013 15" Retina (A1398 EMC 2674) that shows some very strange behavior. I've been looking through the forums and tried a few things, but nothing worked thus far. I might have an idea, but i have absolutely no experience with hardware. I appreciate any help!
What i know about the device:
- Prior the me messing with it, the macbook hasn't been turned on for at least 1,5 years.
- When it was last used, it may or may not have worked.
- Has been used a lot, with visible dents and scratches.
- It has been opened before, some case screws are missing.
The weird behavior:
When pressing the power button, only the fans turn on for a few seconds, then turn off for a second, then turn on again. This cycle continues for a while (between 10-120 minutes, it varies a lot), then the usual booting happens (chime, apple logo with progress bar) up to the point where the progress bar is filled. There, it gets stuck indefinitely on the booting screen. If i restart the machine at that point, by holding the power button and pressing it again, the macbook boots normally. When booted, the macbook behaves normally in almost any aspect, apart from (what i would guess is) rebooting randomly. Interestingly, when the macbook has been running for a while, normal rebooting workes mostly fine. Even when shutting it down, waiting up to ca. 20 minutes, and turning it on again works most of the time, though if i wait longer, it gets stuck on the fan routine again.
What i've tried:
- Reset SMC/NVRAM/PRAM (when resetting the SMC, the magsafe LED blinks once).
- Disconnected the battery and then holding the power button for 30 seconds.
- Running the macbook with a disconnected battery.
- Reinstalling macOS from a boot stick.
- Running the Apple diagnostic (didn't find anything out of the ordinary).
Sadly, none of that seemed to have affected the issue.
A theory:
There is a particularly large dent right above the magsafe connector, and when i opened the back panel, i noticed some grime on the board of the connector. I tried gently rubbing off the grime with some ethanol, which seemed to have worsend the problem (but hard to be sure, could just be me imagining things). The part in questing is here. My question is now: Could a defect in this part cause any of this? Would it make sense to try and replace it? Charging seems to be working just fine. Down below are two pictures, i hope it's clear what i mean.
Thanks for reading, I appreciate any help!
Questa è una buona domanda?
35 
329 
971 
2 Commenti
Why would it (dc-in board) be the problem if you are getting power into the logic board?? Have you tried taking out the logic board to take a close look, and maybe even clean it completely very (really very) carefully.
da Luis Anniel
You're right, it does seem very unlikely. Is it theoretically possbile for a broken dc-in board to cause this behavior? It's a tempting explaination since that would be relatively easy to fix. As for taking out the board: I'm a little apprehensive since i've never done that before but i guess there's no way around it.
da Jan