Macs booting to a blue screen and stalling

[Digital Sage]

Hey folks,

I've seen this twice now in the past two weeks.

It goes like this :

Client has mac that they describe as 'not booting up'.

Further investigation shows it actually boots to the desktop and stalls, only displaying the background.

Normally I'd suspect hard drive issues here, a bit strange with it making the full journey all the way to the desktop. But in both instances smart reports no errors via my external OS X partition which boots fine.

Here's what I did :

Reinstalled OS X. Yosemite or Mavericks. Then scanned for malware both times it's found geneio and a few other ransoms. Removed then, all fine and dandy.

I believe this is caused by

1. Older versions of OS X and
2. Malware which updates itself, causing a glitch with the older version of OS X, which prevents it from starting up.

It's an easy fix but thought I'd mention it here, in case anyone is scratching their head.

 

[lcoughey]

Just because SMART hasn't logged any errors does not mean the drive is healthy. It is on the same pretense that just because you don't have a fever, it does not mean you aren't sick.

That said, it may just be a system issue, but I don't recommend giving a drive a clean bill of health unless you read and test every sector, preferably while cloning it.

 

[Digital Sage]

I did both of these onsite, so didn't have the time to do a complete read test on every sector of the drive.

Having said that, both systems showed instant improvement once the OS refresh was done, AND malware was removed (The 2nd machine had issues starting up after the OS refresh, until i removed the malware, then it was fine).

Also, i wasn't seeing any issues with the boot process which would suggest hard drive failure or stalling.

But out of interest, what software do you use to do complete sector by sector read tests on a mac?

 

[lcoughey]

Well, we get at least 2 or 3 recoveries a week from cases, as above, but after the tech loses the client's data in the process. We do a full clone and discover that not only was the original problem a head or just a lot of bad sectors, but the tech sent the client home with false security that their system was healthy.

I recommend ddrescue to clone the drive...you could invest in a StarTech Imager, if you want a simple hardware imager.

 

[Digital Sage]

Fair enough... i've done heaps of Mac HDD Swapovers.. and have seen many instances where SMART reports everything is fine, but i can tell it's not.

I guess i've built up a bunch of little 'signs' that this is the case. Beachballing.... also i listen to the hard drive when it's working... common repetitive sounds running over ( click.. whrrr... click... wrrr... click) are another sign... Also, HDD Age... i look at SMART stats like power on cycles, ECC errors and Sector Reallocations. FYI - I used DriveDX and Disk Drill... they cover me for all scenarios.. and i've recovered heaps of data for clients... Mac file system seems to recover a lot easier then Windows via software methods such as Disk Drill.

Most of the time, i'll replace the hard drive. ALWAYS advise time machine full backup at all times... This case was different, very different to what i've seen before. I actually advised customer it was most likely a HDD issues before coming onsite... and found when there, it wasn't the case.

 

[calldrdave]

Check out this article I wrote about Mac repair and tools for testing: https://www.technibble.com/nine-things-need-know-apple-macintosh-repair/