My MacBook Has It’s Mind!
February 25, 2019 1:50 PM Subscribe
When I boot my MacBook, it shows me the login screen, let’s me enter my password, accepts my password, and then starts flashing all over the place. Help!
A picture’s worth a thousand words: https://www.instagram.com/p/BuUfI-Fl8ym/?utm_source=ig_share_sheet&igshid=3257424xa38e
I’ve reset PRAM, NVRAM, and SMC, to no end. I’ve tried to boot into Safe Mode but that causes the same problem. Even trying to boot into the Recovery Mode results in the picture above.
I don’t think it’s a hardware issue, because the screen acts normally up and until I log in.
Any ideas?
A picture’s worth a thousand words: https://www.instagram.com/p/BuUfI-Fl8ym/?utm_source=ig_share_sheet&igshid=3257424xa38e
I’ve reset PRAM, NVRAM, and SMC, to no end. I’ve tried to boot into Safe Mode but that causes the same problem. Even trying to boot into the Recovery Mode results in the picture above.
I don’t think it’s a hardware issue, because the screen acts normally up and until I log in.
Any ideas?
I’m not an Apple Genius, but I had a similar issue with an old iBook (the white plastic kind) many years ago, and the problem was the logic board. The only remedy was to get the logic board replaced.
posted by ejs at 2:04 PM on February 25, 2019 [1 favorite]
posted by ejs at 2:04 PM on February 25, 2019 [1 favorite]
Logic board. Had the same experience.
posted by synecdoche at 2:08 PM on February 25, 2019 [1 favorite]
posted by synecdoche at 2:08 PM on February 25, 2019 [1 favorite]
I had a similar-looking issue with my MacBook Pro last year and the Genius was so quick to say "it's the logic board, we should replace the logic board" that I almost thought I was being scammed.
I hope you are under warranty and have a recent backup.
posted by gauche at 2:09 PM on February 25, 2019 [1 favorite]
I hope you are under warranty and have a recent backup.
posted by gauche at 2:09 PM on February 25, 2019 [1 favorite]
I would guess a logic board issue... except that it'll let you see a normal boot screen and log in.
It may be worth trying to run Apple Hardware Test (if it'll let you). It may also be worth trying Recovery Mode and seeing if it's something with the OS, rather than the hardware.
That said, it's probably a logic board issue. If you're still under warranty, great. If not, it's an expensive repair.
posted by Making You Bored For Science at 2:11 PM on February 25, 2019
It may be worth trying to run Apple Hardware Test (if it'll let you). It may also be worth trying Recovery Mode and seeing if it's something with the OS, rather than the hardware.
That said, it's probably a logic board issue. If you're still under warranty, great. If not, it's an expensive repair.
posted by Making You Bored For Science at 2:11 PM on February 25, 2019
The picture looks like bad video memory (which pretty much takes you back to the "replace logic board" option). Is the login screen displayed at a lower resolution than the main desktop? That would explain why it works until you sign in and it tries to draw a larger screen area, running up against bad memory it didn't need at first.
Bad/corrupt drivers could possibly cause the same thing if the login screen was displayed in a basic generic mode and the desktop in a full-featured mode (but someone who knows more about Macs would need to give you an opinion on that). Did you have any updates recently that might have caused this?
Is there any chance there is another account profile on there that might be using a lower resolution you could log into and test with?
posted by CyberSlug Labs at 2:46 PM on February 25, 2019 [2 favorites]
Bad/corrupt drivers could possibly cause the same thing if the login screen was displayed in a basic generic mode and the desktop in a full-featured mode (but someone who knows more about Macs would need to give you an opinion on that). Did you have any updates recently that might have caused this?
Is there any chance there is another account profile on there that might be using a lower resolution you could log into and test with?
posted by CyberSlug Labs at 2:46 PM on February 25, 2019 [2 favorites]
I had a laptop (non-mac) where this would also happen, although not as consistently as you describe. But the screen would look that way. It turned out, weirdly, to be the power adapter/cable, and in fact the problem would recur every year or two as the replacements would wear out. This is probably not your issue, but it's relatively easy to rule out.
posted by trig at 3:39 PM on February 25, 2019
posted by trig at 3:39 PM on February 25, 2019
(also, out of curiosity: if you just stay at the login screen without advancing, does the effect still happen after some time has passed?)
posted by trig at 3:47 PM on February 25, 2019
posted by trig at 3:47 PM on February 25, 2019
Seventeen years of fixing Macintosh hardware tells me that's a failing video card/MLB. If you have access to an external monitor, you can confirm if it is indeed the case by plugging it in. If the pattern repeats on the monitor, it's beyond all doubt.
There can be other causes—I've seen a few (very rarely) cache-induced video issues over the years—but the first step I'd take as a technician would be to plug in the external monitor to confirm my hunch.
posted by los pantalones del muerte at 7:07 PM on February 25, 2019 [1 favorite]
There can be other causes—I've seen a few (very rarely) cache-induced video issues over the years—but the first step I'd take as a technician would be to plug in the external monitor to confirm my hunch.
posted by los pantalones del muerte at 7:07 PM on February 25, 2019 [1 favorite]
Odd that it does not show that distortion until you log in. Did you try booting from Recovery Mode? Does the same problem persist there?
posted by dubious_dude at 8:37 PM on February 25, 2019
posted by dubious_dude at 8:37 PM on February 25, 2019
Best answer: fwiw, if you’re running a reasonably recent macOS with disk encryption enabled, the initial login screen is displayed by the EFI firmware prior to the the disk being unlocked or the OS being available - I expect this uses a significantly slower/dumber video driver, so if the issue is GPU failure then the symptom still fits.
posted by russm at 8:44 PM on February 25, 2019
posted by russm at 8:44 PM on February 25, 2019
This thread is closed to new comments.
posted by JPowers at 1:52 PM on February 25, 2019