Horizontal Line on startup / boot

I just posted a similar problem. Have you tried forcing the laptop into running the Discrete Video all the time. If you go into the System Preferences, under Energy saver, uncheck the box for "Automatic graphics switching." This will cause your machine to use the more energy expensive Discrete Video Card and not allow the machine to switch to the Integrated Video Card.

If that helps, the problem may not be with your graphics cards, it may be with the hardware that does the switching, or the drivers that control them.

I have the same issue with my MacBook Pro 17", Late 2011. I took my machine in for repair on December 30th because of the faulty GPU recall. They replaced the logic board, however, they said the machine moved to legacy status while it was in for repair and as a result, they would not warranty the work performed. My machine currently reboots when performing any task that is graphic intense. Upon reboot, the machine will enter a reboot loop, restarting before the OS starts to load. It will continue to do this until it is cool. After it has cooled, it will work fine for a while and then the same issue will occur. According to the temperature monitor, the temperature never rises above ~70 C. It doesn't feel excessively hot, so I don't feel it is a temperature issue. The same pixelated horizontal bar appears during boot. I have an appointment scheduled for Wednesday, but I feel the machine was not fixed properly and they should cover the cost.

Just had the same experience with an early 2011 15" MBP running Sierra after replacing the hard drive with a Samsung Evo SSD and replacing the RAM with 16 GB Crucial memory. I reset the PRAM and SMC with no effect.

Other than producing that pixilated bar during boot, the Mac doesn't have any issues. In fact, it runs great with the upgrades. Any further word on what's causing this?

Same problem for me...

- Multi-coloured horizontal lines at boot followed by rapidly failing GPU

- Apple agreed to replace the MB again (this was the second time)

- I think they put in a new GPU (It's now a AMD Radeon HD 6770M)

- Multi-coloured lines persisted during boot until I reinstalled Sierra by redownloading from the App Store

- Lines disappeared, all working nicely

I swapped out the new RAM and EVO for the original parts. No change. I put the EVO into an enclosure and booted to it from my Mac. No issues on boot. I've recommended to my client that he bring his Mac to Apple to have them do a hardware test.

Update: I had my client take his 2011 MacBook Pro to the local Apple Store to have them check the hardware. The genius told him that Apple has sent out a bulletin about this start-up issue. They've had lots of complaints about it and it is caused by a firmware issue. They're working on a fix.

I already had logicboard officially replaced by apple last year, I was so confidence that GPU problem would never bother me again...on mavericks and yosemite, yes my MBP 15" early 2011 was so powerful, powered by 8GB RAM and SSD.. after upgraded to sierra this horizontal line appear, exactly same issue like this...to me its mean that new logicboard, higher RAM, and SSD just waste of money... we forced to buy a newest macbook.

I'm having same issues with a 2010 mac pro (posted here: Mac Pro showing horizontal static line when booting ). Also running macOS Sierra, for what its worth.

Hi,

The issues don't match exactly with those listed by the following Repair Program, but your model of MBP is one that is covered under the program. I'd look into it. https://www.apple.com/support/macbookpro-videoissues/

Hi,

I have this issue too, since the latest update 10.12.1 on my late 2011 MBP 15''.

It works fine, but only this grey lines during few seconds on boot.

-> In my opinion, it could be a little Sierra issue regarding the auto-switch between the 2 graphic cards on this model during the startup (?)

Best.

Ok, sounds good :-)

It's not ok. It's a graphics card fault.

Monitor it and return to the Apple store when it happens again (and it will). My MBP of the same era was eventually replaced under the repair program for exactly the same symptoms (after three new logic boards!!)

Hi there,

I have this same exact issue on my early 2011 MacBook Pro. What's weird is it started right after I reset the SMC and PRAM for an unrelated issue that I was trying to solve. After this happened I reset them again but it has continued. I already had my logic board replaced once and I believe it was done under this program. Will they do it a second time?