MacBook Pro start up fails: blue-grey screen

disk1s1: device is not readable.

disk1s1: IO failed, error = 13.

That's not normal and suggest a hard disk drive / SSD not working properly, or its SATA cable or connector is faulty. The latter seems to be fairly common but is easily fixed. Is that SSD original or did you install it? Some of them just don't work well with High Sierra.

The devices are numbered sequentially in the order they're found. disk1s1 is usually an internal one.

Apple Diagnostics is only useful if it identifies a specific fault. Apple's diagnostics are more thorough, but if a particular hardware component is present and working as expected, it's not going to indicate anything wrong either.

Some aftermarket SSDs work well and complaints are literally unheard of: examples include OWC / MacSales "Mercury" series. Others are notoriously unreliable and prone to failure: examples include Samsung "EVO" series. If you have one of them throw it out.

I assume you mean a conventional hard disk drive? Not an optical drive which makes no sense.

If the cable is really $50 I agree that's a lot to spend but the alternative (logic board) is certainly cost-prohibitive. I don't know what the problem was with the problematic ribbon cables on that model but I'm certain it isn't something that could be seen with a naked eye. Look around for a cheap one, perhaps an identical MBP being sold for parts. The problem is certainly related to disk I/O but those are the only three relevant components.

A 2011 model MBP is probably beyond Apple's ability to service any more anyway. Their recommended fix would be a new one.

If you are interested in board level component repair (vs. replacement for ± $800... if you can find one) there are options. None of them are particularly attractive. If you are in the US, PowerBook Medic is knowledgeable and competent, and their prices seem too good to be true. Beware that turnaround time may take months.

Component level repair has become a lost art. Vendors are few and competent ones are practically nonexistent.

It appears the site Hosts removed your description of the fix. I can understand their reasons for doing so, since it is highly unscientific, difficult to control and unorthodox at best, along with a high likelihood of failure and even personal injury.

But I know what you did and I'm glad it worked out for you. As I wrote Apple won't fix that Mac any more, leaving you with only extremely limited and expensive repair alternatives that might not last very long anyway. Good job.

I read with interest your issues as have the exact same situation. Based on the writings, it appears as if you solved the gray screen issue, however, I am unable to locate the directions. Therefore, would you please email the instructions as I am at a total loss on next steps other than purchasing a new device.

Thanks so much for any assistance you can provide.

[Email Edited by Host]

My Macbook Pro 15 i7 late 2011 had the same symptoms starting yesterday after an automatic overnight update, after reading your post and the miracle thing I decided to try the same you did and it finally got to the logon screen, but it took much more then 5 reboots..

Can't open Photos, the Macbook freezes and reboots.

I think it's a faulty video card since I can't open the Photos app or connect the video cable to transmit to the TV.
In both cases the Macbook freezes and reboots.

Today it took about 20+ boots to get to the logon screen... I'm getting desperate.

For what it is worth, I updated my Late 2011 15" MBP to High Sierra a few days ago. It worked great until I finally accepted the nagging security update reminder and finally downloaded that update. It did exactly what it is doing on the original asker's computer. I see a grey screen after the loading bar has gone somewhere in the middle and then an endless restart loop. The last time it happened, I had upgraded to High Sierra from Yosemite in-place (no fresh install) and then eventually applied security updates to High Sierra. Next, it happened again on a fresh install of High Sierra, as soon as security updates were applied. This time it also showed me a blue screen at times, and actually booted once or twice only to fail and go back to that blue screen failed state.

The OS on this machine has been always been updated and no fresh OS was installed on it since early 2012 (I think it came with OSX Lion). I had also broken some configuration because of which some things took a long time and I had a lot of things to start suspecting for the issues, software and hardware when it first started acting up and going into grey-screen + restart loop initially.

I initially tried all the diagnostics steps OP describes in their post except the recovery step because my internal keyboard is partially broken and I use an external keyboard which does not get recognised at that stage in the boot sequence. After all that I could do, I suspected my hard drive may have finally given up since the verbose mode showed many i/o failures and such.

I was fortunate to have another hard drive handy, so I formatted and did a fresh install of High Sierra again on this machine. It worked fine for the first few hours until the security update popped up. I thought it would be good to apply this update, but what did I know. The machine started going back into the blue screens and grey screens and restart loops as soon as this security update was applied.

I somehow think the security update (sorry, I didn't note its reference number) broke my old macbook pro (late 2011), again. I will do another fresh install of High Sierra (and not apply security updates this time) and see if that changes anything. Why upgrade to High Sierra at all? Well, I wouldn't do it if Apple and a lot of other applications I need to use weren't troubling and shaming me for using an old system. Some of them even refuse to install on 10.10 including the new version of the behemoth XCode. And if I run an old compatible XCode on this system, all sorts of things including homebrew starts breaking up with me.