iMac hangs - hardware or software?

Hussman

Hussman

Hussman

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Joined
1 Nov 2003
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1,259
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Maidstone, Kent
Hi,

I have a late 2012 iMac, purchased from new. Been working faultlessly until about a month ago.

I first noticed that webpages would load slowly and I often saw the spinning pizza of death.

It was like the CPU was working on a very intensive task, then would run the other tasks at a lower priority.

I opened activity monitor and nothing odd was immediately obvious. The 3.2Ghz processor was operating at less than 25% most of of the time. Memory (I have 8GB) was also only about a quarter used.

As it was mainly during browsing I assumed it was a plug-in. I uninstalled Chrome and reinstalled it. Same issue.

I then began to notice the hangs and lock ups would happen when using other programs too.

I thought it might be my 2 toshiba external USB drives. So I removed them, but the hangs and slow downs still continue.

I was running Mavericks, so I bit-the-bullet and installed Yosemite hoping this would fix things. It didn't. :(

I have run the apple hardware test and it shows no errors.

I am considering doing a completely fresh "format and rebuild" but this scares me a little as I'm not that knowledgeable about Mac iOS. I need by iMac for work so it's important I don't knobble it.

Also, I'm concerned that as I have a time capsule that backs up all my data (using time machine) if I do a fresh install and then reload my old data I will re-introduce the problem.

Any ideas please fellas??

Hussman

PS: Thanks for reading this far! :)
 
The same problems/symptoms as well as a random shutdown have haunted my rMBP through a couple of fresh installs of both Maverick and Yosemite. I notice the hangs in Safari also but it's been suggested that my problems are with hardware, just something to consider.
 
Hussman said:
Any idea what hardware in particular?

Like I said, the apple hardware test seems to say all is ok.
Click to expand...

I'm afraid not, everything checks out OK on mine too. It mostly happens when I maximise a Safari window and try to scroll too soon. Perhaps someone will have a clue but I was told there's not much to do other than take it to apple.
 
Ok, spoke to Apple and they suggested do the full AHT, not just the basic one.

This flagged up an error with the SATA drive.

Restarted iMac and pressed command and r. Entered the options menu and selected disk utility.

Chose repair disk. Came back 3 hrs later and iMac "appears" to be working ok again.

Not sure how long it will last, but all things seem ok after 24 hrs.

Hussman
 
Hussman said:
Ok, spoke to Apple and they suggested do the full AHT, not just the basic one.

This flagged up an error with the SATA drive.

Restarted iMac and pressed command and r. Entered the options menu and selected disk utility.

Chose repair disk. Came back 3 hrs later and iMac "appears" to be working ok again.

Not sure how long it will last, but all things seem ok after 24 hrs.

Hussman
Click to expand...

Just tried the same thing and got the same error. Will try the fix also and report back.
 
Run AHT again as it is a hardware test and disk utility fixes 'soft' errors - so it may just temporarily mask an underlying problem by 'fixing' accumulated damages indexes etc...
 
Update

Ok, update for anyone who cares...

Found an external USB 3.0 120Gb SSD hanging off my PC.

Used disk utility to fix the iMac internal HHD as best as it could.

Booted up and immediately went to App Store and downloaded Yosemite.

Attached the 120Gb to the iMac and used disk util to format it.

Installed Yosemite onto the SSD. All worked ok. Went to sys prefs and changed boot drive to the SSD.

Rebooted, all worked well. Much better than before. No beachballs!! :cool:

Bought a Samsung 840 Evo 750Gb SSD (from OCUK ;)) and connected it to my iMac via thunderbolt (Seagate Goflex STAE127). How much for the the goflex!!!? :eek::eek::eek:

How much for the thunderbolt wire!!!? :eek::eek::eek: :eek::eek::eek:

Installed Yosemite onto the 750Gb SSD.

Returned to Sys Prefs and selected 750Gb to be boot drive.

Rebooted. All good!

Tried to use my Time Capsule to reload all my old files but, for some reason, it would not play. Kept freezing over long periods of time (2hrs+). :rolleyes:

Used migration assistant to copy files and settings from internal HDD. It borked once, but I re-tried it (with fingers crossed) and it worked ok second time round.

Perhaps not the cheapest solution, but at least I can now maximise the speed advantage of SSDs. Also, as prices reduce, I can just swap out the SSD for a higher capacity one should I need it.

Thanks for the help chaps!

Hussman out.
 
Glad you got it fixed, dude.

I've managed to hammer out a pattern for my freezes and it seems to happen only in Safari when the mouse hasn't moved in a while. When I try to scroll down or anything it just freezes and reboots.
 
Hussman said:
Might be an obvious thing to say, but do you need to use Safari?

Does the same happen with other browsers?
Click to expand...

I've found that Chrome just ruins the battery life and gets noticeably warmer but I've been using it for a few days and no incidents yet but that's not saying much.

Thanks for the tip about the cache, that'll be my next step if there are no issues with Chrome. :)
 
Hussman said:
Don't forget you have other browser options too.

For example Opera and Firefox
Click to expand...

Yeah I tried FF when I first got the mbp but this issue didn't exist then, I think I stopped using it because it was almost as bad as chrome for heat and battery.

The problem is that they switch to the nvidia card way too often whereas safari is made to make the most of the intel card. That along with keychain has just kind of made it my default to be honest. I'll look at opera though, don't remember using that on here. :)
 
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