iMac Urgent Help

Hi all,

I am in need of some help with my iMac 2012. I encountered a problem a while a back which resulted in me needing to reinstall OS X. All was perfect, until roughly a week ago when I turned off the Mac. When I turned it back on in the morning, it took ages to load up, and then was extremely laggy, slow and unusable. After restating a few times, it wouldn't load up at all. I booted into recovery mode and verified the disk, which showed what appeared to me as a minor error, where a value was a digit out which it repaired. However, it still wouldn't load. I have been away but upon getting back, I have reinstalled OS X using the recovery mode. The Mac now boots, but is still laggy and unresponsive. I have also tried resetting the VRAM (think that's what it's called) but have no luck. It strangely doesn't seem to recognize my keyboard, and comes up with Bluetooth assistant upon booting up. Apple Hardware test shows no errors.

Does anybody know what to suggest?

Thanks.

Weaselboy said:

That sounds like a bad drive. It also could be a bad drive cable or logic board failure, but both of those are much less likely.

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Can it be a drive failure despite the fact that disk utility shows no problems whatsoever?

Weaselboy said:

Yes it can.



When you say you had a problem before, what was that issue?



If you did not install anything that broke the OS, things don't just stop working on their own unless there is a hardware failure of some sort.

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The problem that happened before was that I restarted the Mac for an update, and it got stuck on a white screen. I had to reinstall the OS and it came back like brand new. I stupidly don't have a backup of my data.

What do you recommend in terms of getting it all off?

Thanks.

Weaselboy said:

Just get any USB3 external drive in the size you need and use the included Time Machine software to do a full backup. This WD My Passport drive is fairly popular and you can find them at most any electronics store.



I'm guessing the issue you had applying that earlier update was caused by the same drive problem. You can try running the Apple Hardware Test to see what that turns up, but the AHT does not seem to be too good at diagnosing bad drives.

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I have done an Apple Hardware Test and that showed no problems whatsoever. Do you think it's best to turn off the Mac until I get the external HDD, as it's incredibly unresponsive at the moment? It just seems incredibly strange that it was incredibly fast one day, and the next morning it's unresponsive. It's a fusion drive by the way.

Weaselboy said:

Yes, I would definitely turn it off until you can get it backed up.

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Thanks. I did just try to search for activity monitor using spotlight, but it said I couldn't because it was indexing. Does this mean anything?

Weaselboy said:

If Spotlight is reindexing that will certainly slow down the whole system. The question then is why is Spotlight doing a reindex. This happens when the existing Spotlight index is corrupted and Spotlight does a reindex... this adds to my suspicions you have a bad drive.

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Thanks you very much for your help. I will go out and purchase an external hdd tomorrow and backup my data. What's best to do; a time machine backup or just copy over the necessary files?

Weaselboy said:

I would do a full TM backup to you are certain not to miss anything.

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Okay thanks. How does that work exactly; is it an image file or are all of my files accessible individually?

Weaselboy said:

No, its not an image and you can manually access files later.



The best way though is (assuming you have a new, blank drive installed) is to option key boot to the Time Machine drive. That gets you to a recovery screen where you can format the new disk then restore everything from the disk.

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Thanks. It is extremely unresponsive however. For example, it takes a good 2 minutes to load up the icons in Finder. Would it be best to create an image using disk utility in recovery mode, and then attempt to use Time Machine, or shall I just attempt to use Time Machine straight away?

Weaselboy said:

Yeah... it if is that laggy. You might be better off just making a clone with DU from recovery.

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Thanks. Will do. Can the drive store the image, and the Time Machine backup? Also, is it possible to extract files from the image?

Weaselboy said:

Sure... you could make two partitions on the drive. Then use DU in recovery to clone to one partition, then TM normally to the second partition.



If you clone with DU, it won't be an image of any kind... it will be a straight up flat file set on the drive just like your current drive. You will be able to option key boot to the clone and run your computer normally, albeit a little slower due to USB. Actually, this would be a good troubleshooting test. Do the DU clone then option key boot to it and use the machine for a bit to see if the issue is fixed.



To do the clone just command-r to recovery then start DU and go to the restore tab. Then put Macintosh HD in the sours section and your external USB volume in the destination then click restore. This will make a complete copy/clone of the drive that is bootable.

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I see, thank you very much. Disk Utility is still doing the tests very quickly and passing them all. It just seems strange to me that the Mac has gone from slow and unresponsive, to unbootable, and then back to being slow and unresponsive with a reinstall of the OS. Is it possible that something that isn't changed by a reinstall is slowing it down, or are you pretty sure it's a fusion drive failure?

Weaselboy said:

If you wiped the drive, then did a clean install... that would eliminate a third party utility or some app as the culprit. What you are describing sounds just like a drive failure. That Spotlight reindexing on its own make me think that even more.



Like I said, it is certain possible it is a bad drive cable or even the entire logic board that is bad, but those are much less common issues.

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I see. Not sure if it's relevant to this at all, but ever since I got the Mac, there has been a clicking noise randomly. Sometimes they're one after the other, and other times I may only get one per day. It sounds like a slight electrical shock type of noise. I just turned off the Mac and it started clicking. I unplugged it at the wall and still it clicked. Any ideas on this, and are they linked? Thanks for all your help.

Weaselboy said:

A dying hard drive can make a bit of clicking noise sometimes, but it would not do it while unplugged. It might do it a couple seconds just after being unplugged though as the drive spins down. Does that sound like it might be the case?

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Sort of. Will mention it at the store on Thursday. Thanks for your help.

Weaselboy said:

A dying hard drive can make a bit of clicking noise sometimes, but it would not do it while unplugged. It might do it a couple seconds just after being unplugged though as the drive spins down. Does that sound like it might be the case?

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Quick update. Just got back from the Apple Store. They ran a test on the drives, which showed that the HDD had failed. That's now getting repaired and I should have it back in a few days. Before though, I went out and bought a 2TD WD My Passport for Mac, and took the Mac into a local computer shop to attempt to retrieve their data, seeing as the Mac was unbootable and I didn't have any advanced tools. They managed to boot off an external HDD and use some software to retrieve all of my files at a very low price. So overall, no real damaged caused. All my data is safe, and I'm getting a new HDD for the Mac. Thanks for all your help.