Re: Strange iMac freezes

[Neil Houghton]

Hi Daniel,

Thanks for the info & suggestions.

I don't think it is a heating problem. I used fan control software for quite a 
while when the original HD failed and I was running from my backup clone on an 
external drive. However when I replaced the HD and installed the SSD I used the 
OWC provided temperature sensor/lead and now the inbuilt system temperature 
control seems to work well. The HD fan seems to run a little faster than the 
original setup (maybe the 3TB Toshiba generates a bit more heat than the 
original 1TB drive) but iStat menus shows all temperatures as normal and fans 
ramping up as required.

Previously, on hot days, the internal temperatures did rise enough to get the 
fans speeding up a bit (as expected) but never gave any problems. The problems 
have just been apparent this week when temperatures have not been high and fan 
speeds have been normal.

The hard drives were my first thought - which is why I booted from an external 
drive and ran the full disk utility repair process on all internal drives an 
volumes - which showed no problems. Since AHT IS showing a RAM problem I think 
I need to address the RAM first. If I get rid of the currently indicated RAM 
problem and find that I still have ongoing problems then I may need to look at 
installing the combo update or look at more extensive HD testing - but I prefer 
to address one thing at a time to give me a better feel for the problem.

I tried downloading remember but OSX won't let me open it because it is from an 
unidentified developer. I tried clicking the "open anyway" button but it still 
won't open - gives the same message. I guess I could change my security 
settings to allow apps downloaded from anywhere - but I'm reluctant to do that. 

I did read the Remember documentation though and note that it says:
--
Try the Apple Hardware Test CD or DVD first!
Macintosh computers currently ship with a version of the Apple Hardware Test 
(AHT), which can perform some fairly heavy duty memory tests on a computer. 
This should be one of the first lines of defense in diagnosing computer 
problems. Although the AHT test are thorough, they have not proven to find all 
defective memory. If these tests do not find the problem, then give Rember a 
try.

AND:
If have experience replacing hardware, the only way to locate defective memory 
chips is by deduction - guess and check or split-half method troubleshooting. 
This may be updated in the future. You may also attempt to run the Apple 
Hardware Test CD or DVD that comes with most Macs. This may give more 
information (if it finds the problem).
--

So it would seem that Remember won't actually indicate which module is faulty - 
and since AHT is already indicating a problem the maybe I just need to try the 
suggested deduction ;o)

The computer has been running OK since yesterday - but doing next to nothing as 
I work on the laptop - so I will run AHT again to be sure it still sees the 
problem - and then probably try the split-half method trouble shooting.

I will keep you informed on progress.


Cheers


Neil


On 13/03/19, 21:28, "Daniel Kerr" 
 wrote:

Hi Neil

Just a quick reply as finishing off some other work.

A few things I would run to test it.
(sometimes I find Apple RAM test not all that helpful, whereas the 
following is very good).
Just be aware it can take a really really long time to test it all, as it 
does a huge amount of tests to all the modules. (I’ve seen some take hours to 
complete - 
Rember - http://www.kelleycomputing.net/rember/

I’d also run the hard drives just to rule them out. For a good program I 
use Smart Disk Utility from here - 
(the demo is fine for a one off test).
https://www.volitans-software.com/apps/smart-utility/

Could also be something “heating up” perhaps? So it runs for a while, until 
a part is heated up a bit more. (unlikely, but worth a check anyway).
For older iMac’s that have had hard drives replaced this is a good program 
to help control the Fans a bit more then the Apple one - 
http://www.hddfancontrol.com

But I’d be checking the RAM first would be my start.

Hope something there helps. If I think of more, I’ll post back as well.
Kind regards
Daniel

---
Daniel Kerr
MacWizardry

Phone: 0414 795 960
Email: 
Web:   


**For everything Apple**

NOTE: Any information provided in this email may be my personal opinion and 
as such should be taken accordingly, and may not be the views of MacWizardry. 
Any information provided does not offer or warrant any form of warranty or 
accept liability. It would be appreciated that if any information in this email 
is to be disseminated, distributed o

Re: Strange iMac freezes

[Daniel Kerr]

Hi Neil

Just a quick reply as finishing off some other work.

A few things I would run to test it.
(sometimes I find Apple RAM test not all that helpful, whereas the following is 
very good).
Just be aware it can take a really really long time to test it all, as it does 
a huge amount of tests to all the modules. (I’ve seen some take hours to 
complete - 
Rember - http://www.kelleycomputing.net/rember/

I’d also run the hard drives just to rule them out. For a good program I use 
Smart Disk Utility from here - 
(the demo is fine for a one off test).
https://www.volitans-software.com/apps/smart-utility/

Could also be something “heating up” perhaps? So it runs for a while, until a 
part is heated up a bit more. (unlikely, but worth a check anyway).
For older iMac’s that have had hard drives replaced this is a good program to 
help control the Fans a bit more then the Apple one - 
http://www.hddfancontrol.com

But I’d be checking the RAM first would be my start.

Hope something there helps. If I think of more, I’ll post back as well.
Kind regards
Daniel

---
Daniel Kerr
MacWizardry

Phone: 0414 795 960
Email: 
Web:   


**For everything Apple**

NOTE: Any information provided in this email may be my personal opinion and as 
such should be taken accordingly, and may not be the views of MacWizardry. Any 
information provided does not offer or warrant any form of warranty or accept 
liability. It would be appreciated that if any information in this email is to 
be disseminated, distributed or copied, that permission by the author be 
requested. 

> On 13 Mar 2019, at 8:52 pm, Neil Houghton  wrote:
> 
> Hi Ronni,
>  
> The problem is that all RAM modules show as OK both in System report and 
> Etrecheck (which says the performance is Excellent) and it seems that the 
> iMac thinks I have a fully functioning 24GB.
>  
> It is obviously something that only shows up in the more heavy duty checks 
> that AHT uses.
>  
> The problem is that the error message does not seem to indicate which module 
> is problematic - so I guess it is trial and error and repeated use of AHT?
>  
> Thanks
>  
>  
> Neil
>  
> From:  on behalf of Ronni 
> Brown 
> Reply-To: 
> Date: Wednesday, 13 March 2019 at 17:52
> To: 
> Subject: Re: Strange iMac freezes
>  
> Hi Neil,
>  
> Yes that AHT does indicate Bad Ram. On your menu bar go to: Apple > About 
> This Mac > click on System Report... > then click on Memory in the Hardware 
> section.
> 
> 
> There you should be able to see which 0xb740bf98  module has failed and which 
> slot it is installed in.
> 
> Kind Regards,
> Ronni
>  
>  Ronni Brown’s iPad Pro 12.9-inch 256GB 
>  
> 
> On 13 Mar 2019, at 5:18 pm, Neil Houghton  wrote:
> 
>> OK - prior to running the combo update I thought I’d run a couple more tests:
>>  
>> 1)  I ran the Apple Hardware Test (AHT) in extended mode and it did report a 
>> problem (on pass 1):
>> 4MEM/9/400 0xb740bf98
>> which I understand indicates a RAM problem.
>>  
>> 2)  I then ran Etrecheck which reported no problem except
>> Last shutdown cause - 128- unknown
>> However the time of this shutdown would match me hitting the shutdown button 
>> in Apple Hardware test - so not really a problem.
>>  
>> So, my current thinking is:
>>  • AHT is finding a RAM problem
>>  • The RAM passes the normal bootup RAM check
>>  • Etrecheck shows all RAM modules check out OK
>>  • The problem could be a (few) bad sector(s) on one RAM module
>>  • Everything works fine until something tries to access the bad RAM 
>> sector(s)
>>  
>> I guess I now need to isolate the bad RAM module. Given I have 24GB RAM in 4 
>> modules then, assuming there is just one problem module, the iMac should 
>> continue to work fine on either 20GB or 16GB (depending on the size of the 
>> faulty RAM) while I get the bad RAM replaced.
>>  
>> I may or may not need to run the combo update - depending on whether the 
>> various hard shutdowns have caused any corruptions problems.
>>  
>> I will keep you informed on progress.
>>  
>> Cheers
>>  
>>  
>> Neil
>>  
>> From:  on behalf of Neil 
>> Houghton 
>> Reply-To: "wamug@wamug.org.au" 
>> Date: Tuesday, 12 March 2019 at 17:20
>> To: "wamug@wamug.org.au" 
>> Subject: Re: Strange iMac freezes
>>  
>> OK - further update - another freeze:
>>  
>> This time only MS Outlook was running and I was previewing attachments to an 
>> email (using the Outlook preview all button when the spinning beachball 
>> appeared.
>> At first I could see both Outlook and Finder using the command-tab switcher 
>> and checking the fast user switching drop-down menu worked OK - showing my 
>> user account logged in.
>>  
>> Then more strangeness happened:
>>  • All my desktop items “disappeared” though the desktop picture was 
>> still visible (if this had happened at the last freeze when using Firefox I 
>> would not have noticed since the desktop was obscured by the 2 Firefox 
>> windows)
>>  • Command-

Re: Strange iMac freezes

[Neil Houghton]

Hi Ronni,

 

The problem is that all RAM modules show as OK both in System report and 
Etrecheck (which says the performance is Excellent) and it seems that the iMac 
thinks I have a fully functioning 24GB.

 

It is obviously something that only shows up in the more heavy duty checks that 
AHT uses.

 

The problem is that the error message does not seem to indicate which module is 
problematic - so I guess it is trial and error and repeated use of AHT?

 

Thanks

 

 

Neil

 

From:  on behalf of Ronni Brown 

Reply-To: 
Date: Wednesday, 13 March 2019 at 17:52
To: 
Subject: Re: Strange iMac freezes

 

Hi Neil,

 

Yes that AHT does indicate Bad Ram. On your menu bar go to: Apple > About This 
Mac > click on System Report... > then click on Memory in the Hardware section.




There you should be able to see which 0xb740bf98  module has failed and which 
slot it is installed in.


Kind Regards,

Ronni

 

 Ronni Brown’s iPad Pro 12.9-inch 256GB 

 


On 13 Mar 2019, at 5:18 pm, Neil Houghton  wrote:

OK - prior to running the combo update I thought I’d run a couple more tests:

 

1)  I ran the Apple Hardware Test (AHT) in extended mode and it did report a 
problem (on pass 1):

4MEM/9/400 0xb740bf98

which I understand indicates a RAM problem.

 

2)  I then ran Etrecheck which reported no problem except

Last shutdown cause - 128- unknown

However the time of this shutdown would match me hitting the shutdown button in 
Apple Hardware test - so not really a problem.

 

So, my current thinking is:
AHT is finding a RAM problem
The RAM passes the normal bootup RAM check
Etrecheck shows all RAM modules check out OK
The problem could be a (few) bad sector(s) on one RAM module
Everything works fine until something tries to access the bad RAM sector(s)
 

I guess I now need to isolate the bad RAM module. Given I have 24GB RAM in 4 
modules then, assuming there is just one problem module, the iMac should 
continue to work fine on either 20GB or 16GB (depending on the size of the 
faulty RAM) while I get the bad RAM replaced.

 

I may or may not need to run the combo update - depending on whether the 
various hard shutdowns have caused any corruptions problems.

 

I will keep you informed on progress.

 

Cheers

 

 

Neil

 

From:  on behalf of Neil 
Houghton 
Reply-To: "wamug@wamug.org.au" 
Date: Tuesday, 12 March 2019 at 17:20
To: "wamug@wamug.org.au" 
Subject: Re: Strange iMac freezes

 

OK - further update - another freeze:

 

This time only MS Outlook was running and I was previewing attachments to an 
email (using the Outlook preview all button when the spinning beachball 
appeared.

At first I could see both Outlook and Finder using the command-tab switcher and 
checking the fast user switching drop-down menu worked OK - showing my user 
account logged in.

 

Then more strangeness happened:
All my desktop items “disappeared” though the desktop picture was still visible 
(if this had happened at the last freeze when using Firefox I would not have 
noticed since the desktop was obscured by the 2 Firefox windows)
Command-tab now only showed Outlook and NOT Finder - as if Finder had somehow 
quit and not relaunched.
I normally have the dock hidden but the cursor revealed it normally - showing 
no dot under the finder to show it was running.
I clicked the finder icon in the dock (hoping to relaunch finder) and the 
desktop picture immediately disappeared leaving a black background.
 

Currently:
Desktop is black but menubar and Outlook window are still showing.
Mousing over the hidden dock no longer reveals it.
The cursor shows the spinning beachball over the outlook window and menu items
The Outlook window can be moved but not resized
The cursor currently show the normal pointer over the right-hand Apple menu 
icons and the 1Password menu icon
The cursor shows the spinning beachball over the Onedrive and Dropbox menu icons
When the cursor is moused over the Malwarebytes menu icon it says “Background 
service is offline”
When the cursor is moved over the black desktop, it does not change state - ie 
it stays as ether the normal pointer or as the beachball depending what the 
state was just prior to moving onto the “black”
 

Continuing:
With the cursor over the Spotlight icon, it changed to the beachball and then 
the icon disappeared.
Picking on an Apple menu icon to click - this time the wireless status icon - 
resulted in the cursor now showing the spinning ball over all the Apple menu 
icons
Clicking on the 1Password and Malwarebytes menu icons also resulted in the 
cursor changing to showing the spinning ball over these menu icons
This time the other Apple menu icons did not actually disappear from the menu 
bar.
 

The problem has now occurred both with Outlook only running and with Firefox 
only running and It now seems to me that the problem is not with either app but 
with some basic OSX functionality at the finder/dock level (or the processes 
running these functions).

 

I think Ron

Re: Strange iMac freezes

[Ronni Brown]

Hi Neil,

Yes that AHT does indicate Bad Ram. On your menu bar go to: Apple > About This 
Mac > click on System Report... > then click on Memory in the Hardware section.

There you should be able to see which 0xb740bf98  module has failed and which 
slot it is installed in.

Kind Regards,
Ronni

 Ronni Brown’s iPad Pro 12.9-inch 256GB 


> On 13 Mar 2019, at 5:18 pm, Neil Houghton  wrote:
> 
> OK - prior to running the combo update I thought I’d run a couple more tests:
>  
> 1)  I ran the Apple Hardware Test (AHT) in extended mode and it did report a 
> problem (on pass 1):
> 4MEM/9/400 0xb740bf98
> which I understand indicates a RAM problem.
>  
> 2)  I then ran Etrecheck which reported no problem except
> Last shutdown cause - 128- unknown
> However the time of this shutdown would match me hitting the shutdown button 
> in Apple Hardware test - so not really a problem.
>  
> So, my current thinking is:
> AHT is finding a RAM problem
> The RAM passes the normal bootup RAM check
> Etrecheck shows all RAM modules check out OK
> The problem could be a (few) bad sector(s) on one RAM module
> Everything works fine until something tries to access the bad RAM sector(s)
>  
> I guess I now need to isolate the bad RAM module. Given I have 24GB RAM in 4 
> modules then, assuming there is just one problem module, the iMac should 
> continue to work fine on either 20GB or 16GB (depending on the size of the 
> faulty RAM) while I get the bad RAM replaced.
>  
> I may or may not need to run the combo update - depending on whether the 
> various hard shutdowns have caused any corruptions problems.
>  
> I will keep you informed on progress.
>  
> Cheers
>  
>  
> Neil
>  
> From:  on behalf of Neil 
> Houghton 
> Reply-To: "wamug@wamug.org.au" 
> Date: Tuesday, 12 March 2019 at 17:20
> To: "wamug@wamug.org.au" 
> Subject: Re: Strange iMac freezes
>  
> OK - further update - another freeze:
>  
> This time only MS Outlook was running and I was previewing attachments to an 
> email (using the Outlook preview all button when the spinning beachball 
> appeared.
> At first I could see both Outlook and Finder using the command-tab switcher 
> and checking the fast user switching drop-down menu worked OK - showing my 
> user account logged in.
>  
> Then more strangeness happened:
> All my desktop items “disappeared” though the desktop picture was still 
> visible (if this had happened at the last freeze when using Firefox I would 
> not have noticed since the desktop was obscured by the 2 Firefox windows)
> Command-tab now only showed Outlook and NOT Finder - as if Finder had somehow 
> quit and not relaunched.
> I normally have the dock hidden but the cursor revealed it normally - showing 
> no dot under the finder to show it was running.
> I clicked the finder icon in the dock (hoping to relaunch finder) and the 
> desktop picture immediately disappeared leaving a black background.
>  
> Currently:
> Desktop is black but menubar and Outlook window are still showing.
> Mousing over the hidden dock no longer reveals it.
> The cursor shows the spinning beachball over the outlook window and menu items
> The Outlook window can be moved but not resized
> The cursor currently show the normal pointer over the right-hand Apple menu 
> icons and the 1Password menu icon
> The cursor shows the spinning beachball over the Onedrive and Dropbox menu 
> icons
> When the cursor is moused over the Malwarebytes menu icon it says “Background 
> service is offline”
> When the cursor is moved over the black desktop, it does not change state - 
> ie it stays as ether the normal pointer or as the beachball depending what 
> the state was just prior to moving onto the “black”
>  
> Continuing:
> With the cursor over the Spotlight icon, it changed to the beachball and then 
> the icon disappeared.
> Picking on an Apple menu icon to click - this time the wireless status icon - 
> resulted in the cursor now showing the spinning ball over all the Apple menu 
> icons
> Clicking on the 1Password and Malwarebytes menu icons also resulted in the 
> cursor changing to showing the spinning ball over these menu icons
> This time the other Apple menu icons did not actually disappear from the menu 
> bar.
>  
> The problem has now occurred both with Outlook only running and with Firefox 
> only running and It now seems to me that the problem is not with either app 
> but with some basic OSX functionality at the finder/dock level (or the 
> processes running these functions).
>  
> I think Ronni’s suggestion for the combo update is my best bet at this point.
>  
> I will report back with my progress - or lack thereof  ;o)
>  
>  
> Cheers
>  
>  
> Neil
>  
>  
>  
>  
> From:  on behalf of Neil 
> Houghton 
> Reply-To: "wamug@wamug.org.au" 
> Date: Tuesday, 12 March 2019 at 16:02
> To: "wamug@wamug.org.au" 
> Subject: Strange iMac freezes
>  
> Writing this from the laptop as my iMac has started playing up with strange 
> ‘freezes’ the likes of which I’ve

Re: Strange iMac freezes

[Neil Houghton]

OK - prior to running the combo update I thought I’d run a couple more tests:

 

1)  I ran the Apple Hardware Test (AHT) in extended mode and it did report a 
problem (on pass 1):

4MEM/9/400 0xb740bf98

which I understand indicates a RAM problem.

 

2)  I then ran Etrecheck which reported no problem except

Last shutdown cause - 128- unknown

However the time of this shutdown would match me hitting the shutdown button in 
Apple Hardware test - so not really a problem.

 

So, my current thinking is:
AHT is finding a RAM problem
The RAM passes the normal bootup RAM check
Etrecheck shows all RAM modules check out OK
The problem could be a (few) bad sector(s) on one RAM module
Everything works fine until something tries to access the bad RAM sector(s)
 

I guess I now need to isolate the bad RAM module. Given I have 24GB RAM in 4 
modules then, assuming there is just one problem module, the iMac should 
continue to work fine on either 20GB or 16GB (depending on the size of the 
faulty RAM) while I get the bad RAM replaced.

 

I may or may not need to run the combo update - depending on whether the 
various hard shutdowns have caused any corruptions problems.

 

I will keep you informed on progress.

 

Cheers

 

 

Neil

 

From:  on behalf of Neil 
Houghton 
Reply-To: "wamug@wamug.org.au" 
Date: Tuesday, 12 March 2019 at 17:20
To: "wamug@wamug.org.au" 
Subject: Re: Strange iMac freezes

 

OK - further update - another freeze:

 

This time only MS Outlook was running and I was previewing attachments to an 
email (using the Outlook preview all button when the spinning beachball 
appeared.

At first I could see both Outlook and Finder using the command-tab switcher and 
checking the fast user switching drop-down menu worked OK - showing my user 
account logged in.

 

Then more strangeness happened:
All my desktop items “disappeared” though the desktop picture was still visible 
(if this had happened at the last freeze when using Firefox I would not have 
noticed since the desktop was obscured by the 2 Firefox windows)
Command-tab now only showed Outlook and NOT Finder - as if Finder had somehow 
quit and not relaunched.
I normally have the dock hidden but the cursor revealed it normally - showing 
no dot under the finder to show it was running.
I clicked the finder icon in the dock (hoping to relaunch finder) and the 
desktop picture immediately disappeared leaving a black background.
 

Currently:
Desktop is black but menubar and Outlook window are still showing.
Mousing over the hidden dock no longer reveals it.
The cursor shows the spinning beachball over the outlook window and menu items
The Outlook window can be moved but not resized
The cursor currently show the normal pointer over the right-hand Apple menu 
icons and the 1Password menu icon
The cursor shows the spinning beachball over the Onedrive and Dropbox menu icons
When the cursor is moused over the Malwarebytes menu icon it says “Background 
service is offline”
When the cursor is moved over the black desktop, it does not change state - ie 
it stays as ether the normal pointer or as the beachball depending what the 
state was just prior to moving onto the “black”
 

Continuing:
With the cursor over the Spotlight icon, it changed to the beachball and then 
the icon disappeared.
Picking on an Apple menu icon to click - this time the wireless status icon - 
resulted in the cursor now showing the spinning ball over all the Apple menu 
icons
Clicking on the 1Password and Malwarebytes menu icons also resulted in the 
cursor changing to showing the spinning ball over these menu icons
This time the other Apple menu icons did not actually disappear from the menu 
bar.
 

The problem has now occurred both with Outlook only running and with Firefox 
only running and It now seems to me that the problem is not with either app but 
with some basic OSX functionality at the finder/dock level (or the processes 
running these functions).

 

I think Ronni’s suggestion for the combo update is my best bet at this point.

 

I will report back with my progress - or lack thereof  ;o)

 

 

Cheers

 

 

Neil

 

 

 

 

From:  on behalf of Neil 
Houghton 
Reply-To: "wamug@wamug.org.au" 
Date: Tuesday, 12 March 2019 at 16:02
To: "wamug@wamug.org.au" 
Subject: Strange iMac freezes

 

Writing this from the laptop as my iMac has started playing up with strange 
‘freezes’ the likes of which I’ve never seen before – and I’ve had my share of 
crashes, freezes & hangs over the years!!

 

First my setup/hardware – which has been “enhanced” since purchase:
27” iMac 2.8GHz i7 - late 2009 - running OSX 10.11.6
24GB RAM - 2x8GB + 2x4GB
Internal Drive 1 - Mercury Electra 250GB SSD - boot drive containing OSX, 
applications and a bare “admin” user account
Internal Drive 2 - 3TB Toshiba partitioned as:
· 1.5TB volume - containing main user folder plus other data folders

· 1.0TB volume - currently empty (earmarked for media files)

· 500GB volume