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rampancy

macrumors 6502a
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Jul 22, 2002
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So I have a Late-2013 iMac running the latest version of Catalina. Up until now, it's been for the most part working fine off of an external Samsung T7 Shield, since the internal hard drive isn't doing well (DriveDx reports it's at 71% health, but it is at pre-fail status for Load Cycle Count; when running off of the drive the system slows to a crawl).

Lately I've been experiencing random spontaneous reboots of the system; I don't recall installing or updating any significant pieces of software, at least none that I can think of which would install potentially problematic stuff like kernel extensions.

What could possibly be the problem? I don't even know where I could find the related post-reboot crash log for me to go through; Console doesn't seem to turn up anything relevant.
 
Re-seat the ram. Run some tests.
I’ve been running Ventura via OCLP on Sonoma on my late-2013 iMac 27” 14,2 Kepler Graphics and just started getting an occasional freeze or reboot. I think it’s on its last leg, but if it will run Sequoia, I’ll try another year to make it last.
 
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Hmm, well, I have decided to open up the iMac at long last and replace the dying hard drive. Maybe reseating or replacing the RAM is worth a shot.

Would using the Apple Diagnostics work as well as using MemTest86? I don't have an available USB drive on hand lying around...
 
No - there's no contest. :)

No USB sticks at all?

That's good to know. I tried using Apple Diagnostics, and it said there were no problems. It didn't even pick up the issue with the hard drive.

And no, I don't have any USB sticks available at all. I'll try to get one tomorrow and see what happens.

In the meantime I am running the Samsung Magician software off of the internal drive. I just did a firmware update, and I'm doing a diagnostic with it now. We'll see what happens.

I'm not thrilled with the prospect of having to replace the RAM in this thing, but maybe it would be a good excuse to upgrade it to a full 16 GB of memory.

I'm not really interested in significantly improving its performance. I just want a Mac that won't spontaneously reboot in the middle of a Zoom call.
 
Re-seat the ram. Run some tests.
I’ve been running Ventura via OCLP on Sonoma on my late-2013 iMac 27” 14,2 Kepler Graphics and just started getting an occasional freeze or reboot. I think it’s on its last leg, but if it will run Sequoia, I’ll try another year to make it last.

Do you think you might have any idea why its freezing or rebooting? What frustrates me is that I really have no idea why my iMac is doing this.
 
That's good to know. I tried using Apple Diagnostics, and it said there were no problems. It didn't even pick up the issue with the hard drive.

Apple's diagnostics software is helpful to an extent in particular areas. Unfortunately, this is not one of them.

I'm not thrilled with the prospect of having to replace the RAM in this thing, but maybe it would be a good excuse to upgrade it to a full 16 GB of memory.

If the RAM is faulty then there's the consolation that it's often the cheapest component to replace or upgrade.

I just want a Mac that won't spontaneously reboot in the middle of a Zoom call.

For some people that would be a welcome escape from video calls! :D

Though, yes that's not a tenable situation. My money is on the RAM or possibly the external drive has been corrupted but I'm convinced that it's related to the memory because I've experienced similar symptoms myself related to defective RAM.
 
Do you think you might have any idea why its freezing or rebooting? What frustrates me is that I really have no idea why my iMac is doing this.
It’s old. Thermal past is drying up. Solder joints are cracking.

Time to go into major debug mode.

You said you use an external drive. Is that connection 100% stable and perfect? Is the drive? They may not be.
 
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It’s old. Thermal past is drying up. Solder joints are cracking.

Time to consider replacing it or go into major debug mode.

You said you use an external drive. Is that connection 100% stable and perfect? Is the drive? They may not be.

That isn’t helpful or instructive advice here on the Early Intel Macs forum.

Our remit is to maintain existing hardware and to tend to them when they need servicing.

Moreover, Apple still, as of this date, support the early 2013 iMac — the education i3 model — as a “vintage” product. These systems were designed to last a very long time. In fact, I’ll be doing my own upgrade and maintenance on my late 2013 A1418, which runs 24/7, in a couple of weeks.

Toss-and-buy-a-replacement may work better on the other sub-forums. Here and on the PowerPC forums, that’s just not what folks here do.

—posted from my early 2011 15-inch MacBook Pro
 
So I have a Late-2013 iMac running the latest version of Catalina. Up until now, it's been for the most part working fine off of an external Samsung T7 Shield, since the internal hard drive isn't doing well (DriveDx reports it's at 71% health, but it is at pre-fail status for Load Cycle Count; when running off of the drive the system slows to a crawl).

Lately I've been experiencing random spontaneous reboots of the system; I don't recall installing or updating any significant pieces of software, at least none that I can think of which would install potentially problematic stuff like kernel extensions.

What could possibly be the problem? I don't even know where I could find the related post-reboot crash log for me to go through; Console doesn't seem to turn up anything relevant.

The first thing to come to mind is ageing thermal efficiency arising from dried thermal paste and dust-caked fans. The system could be going into thermal protection mode. Of course, keeping an eye on the temperature readings would lend to whether thermal limits are being reached (or not).

As I have the same A1418, mine is due for all of the maintenances, and I’m planning for this in the coming weeks. As a routine, my iMac fan is set, via Macs Fan Control, to run at max speed at all times. This has kept it reasonably cool, even during the hot summer we just got through, but I have noted a general, 3–5°C increase in baseline temps, versus when I set it up for the first time back in 2020.
 
If the RAM is faulty then there's the consolation that it's often the cheapest component to replace or upgrade.
I typically wouldn't mind doing a RAM upgrade except that changing/upgrading the RAM necessitates practically a full teardown of the entire machine. I'm no stranger to wading inside the guts of a Mac, but I admit it's an intimidating task.

For some people that would be a welcome escape from video calls! :D
The benefits aren't lost on me either, but I shudder at what would have happened if I was in the middle of writing or working on my website...

You said you use an external drive. Is that connection 100% stable and perfect? Is the drive? They may not be.
The drive is a Samsung T7 Shield and from what I've seen in Samsung Magician, it and the connection are 100% fine. The only issue is what looks like an AFPS snapshot error in Disk Utility that it somehow won't fix - likely due to the random reboots.
 
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Sorry if I offended anyone about replacement.

If OP wants to continue to use this machine for “productivity”, I’d consider replacing that internal drive with an SD, a Mac ram upgrade, etc.

I’ve torn my 27” down to replace the internal PCIE blade SSD. It’s not so bad.

I’ll tell you one thing, doing nothing won’t fix it.
 
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Finally figured it out!

I seem to have run afoul of the dreaded watchdogd timeout kernel panic issue that still dogs Mac users today.

Supposedly there's a ridiculously simple fix that's supposed to cure this (just go to Security and Privacy and remove Terminal from Developer Tools), but we'll see what happens. Maybe I just need to do a complete reinstall of the system.
 
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Finally figured it out!

I seem to have run afoul of the dreaded watchdogd timeout kernel panic issue that still dogs Mac users today.

Supposedly there's ridiculously simple fix that's supposed to cure this, but we'll see what happens. Maybe I just need to do a complete reinstall of the system.

I’ve bookmarked this post on that thread, cheers.

I’ve also bookmarked the following discussion and this post as possible workarounds, as well.
 
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So I spent the better part of last night until 2 am learning the finer points of opening up and cleaning the A1418, since I decided to use this opportunity to replace the dying hard drive, and upgrade the memory. Whoever thought of using adhesive tape to put together a $1300 computer needs to be subjected to The Most Annoying Sound in the World for the next decade.

And whoever decided to put a 5400 rpm hard drive in it deserves to daily drive one of these for the rest of their life.

And...I have some words for the folks on iFixit who said, "You don't need to extract the motherboard to install RAM! Just remove the fan and shove the memory into the tiny dark tight gap between the case and the motherboard! It's easy!"

I’ve bookmarked this post on that thread, cheers.

I’ve also bookmarked the following discussion and this post as possible workarounds, as well.
The problem with these fixes is that the issue itself is one of the worst (IMHO) you can encounter in terms of software - it's not consistently reproducible and there's no consistent fix. Some people report it's linked to php/Ruby and Homebrew installs. Some people report it's due to SMC issues. I distinctly remember encountering these random crashes after updating some of my paid apps, including iClip and LaunchBar, plus some games like Classic Marathon. Huh!?

At least I'm ~90% certain it's not a hardware issue; I actually had a watchdogd-related kernel panic while I was doing some stress testing of my new upgrades (fittingly enough, the system locked up and rebooted right in the middle of me playing TDNC's video of upgrading a 21.5" Late-2013 iMac with an SSD).

On top of of the issues surrounding the crashing (which I know I can at least solve with an OS reinstall), I've also spooked myself reading various iFixit forum posts, Amazon reviews and Reddit posts talking about how the screen glass would fall out of their iMac after applying the replacement adhesive tape. Drawing inspiration from a 27" iMac thread I decided to order some clear duct tape to use to fix the screen to the case, for extra protection against the adhesive tape failing.


Toss-and-buy-a-replacement may work better on the other sub-forums. Here and on the PowerPC forums, that’s just not what folks here do.

Pretty much this. I got this iMac for free from a childhood friend who I'd helped upgrade to an M1 iMac, and I'll be damned if I'll have to toss this out. If I was able to eke out ~1.5 year's worth of use as a daily driver running it entirely off of an external SSD, I know I can get many more years of use as a primary machine with 16 GB RAM and a new internal SSD.

I thought about potentially caving and just getting an Apple Refurb iMac, but I honestly don't see the point seeing as how this 2013 iMac meets pretty much all of my needs right now. It just needs some patience and a little elbow grease.
 
Whoever thought of using adhesive tape to put together a $1300 computer needs to be subjected to The Most Annoying Sound in the World for the next decade.

That gave me a much needed laugh. I might seek out the entire film. :)

And whoever decided to put a 5400 rpm hard drive in it deserves to daily drive one of these for the rest of their life.

Some of the comments left by viewers are hilariously accurate about the direction that Apple has taken:

This $39 Laptop has more ports than a $1,299 MacBook Pro wow.

Hear this Apple, even a damn $39 laptop has a headphone jack

When a $39 dollar PC got more ports than a $2400 dollar Macbook Pro..... rolfmao...

The amount of likes receives by each of those comments indicates that we're actually far from an isolated bunch on this subject and yes a 5400 RPM HDD instead of 7200 considering that Macs are hardly cheap is annoying, to say the least.

I got this iMac for free from a childhood friend who I'd helped upgrade to an M1 iMac, and I'll be damned if I'll have to toss this out. If I was able to eke out ~1.5 year's worth of use as a daily driver running it entirely off of an external SSD, I know I can get many more years of use as a primary machine with 16 GB RAM and a new internal SSD.

The Silicon models are undeniably the future of Apple but they're not my future. As it stands, there's no reason for me to abandon my Intel Macs because despite the advances in CPU performance, doing so would actually represent a step backwards. Even the supposed top-of-the-line M2 Ultra Mac Pro has no potential for RAM expansion and its max RAM capacity is considerably smaller than that of its Intel based predecessor (192GB vs 1.5TB). There's no eGPU support at all (or even dGPU for that matter) - my 2011 MBA possesses this capability for goodness sake.

My Intel Macs fit my needs and will continue to do so regardless of whether Apple support them. :)

I thought about potentially caving and just getting an Apple Refurb iMac, but I honestly don't see the point seeing as how this 2013 iMac meets pretty much all of my needs right now. It just needs some patience and a little elbow grease.

Which will make it all the more satisfying when you succeed. :)
 
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So I spent the better part of last night until 2 am learning the finer points of opening up and cleaning the A1418, since I decided to use this opportunity to replace the dying hard drive, and upgrade the memory. Whoever thought of using adhesive tape to put together a $1300 computer needs to be subjected to The Most Annoying Sound in the World for the next decade.

By the Most Annoying Actor in the World, no less. Double Word Score!

And whoever decided to put a 5400 rpm hard drive in it deserves to daily drive one of these for the rest of their life.

Oh yes. Craig. The B-minus grade audiophile brand of the ’70s which, by the 1980s, levelled off as the eminent C-minus grade brand of audio just beneath Realistic C-plus), just one step above… Audiovox and Yorx (bronx cheers). Buckle up, because now Craig is getting into… computing.

What could possibly go wrong…

And...I have some words for the folks on iFixit who said, "You don't need to extract the motherboard to install RAM! Just remove the fan and shove the memory into the tiny dark tight gap between the case and the motherboard! It's easy!"

Why Apple made it reasonably easy to swap and upgrade RAM on the 27-inch variant but not for the 21.5-inch models is an object lesson on corporate parsimony.

The problem with these fixes is that the issue itself is one of the worst (IMHO) you can encounter in terms of software - it's not consistently reproducible and there's no consistent fix. Some people report it's linked to php/Ruby and Homebrew installs. Some people report it's due to SMC issues. I distinctly remember encountering these random crashes after updating some of my paid apps, including iClip and LaunchBar, plus some games like Classic Marathon. Huh!?

So in short, it’s the design of macOS after a certain point in its evolution after Craig Federighi entered the chat.

I can’t say I’m stunned.

At least I'm ~90% certain it's not a hardware issue; I actually had a watchdogd-related kernel panic while I was doing some stress testing of my new upgrades (fittingly enough, the system locked up and rebooted right in the middle of me playing TDNC's video of upgrading a 21.5" Late-2013 iMac with an SSD).

On top of of the issues surrounding the crashing (which I know I can at least solve with an OS reinstall), I've also spooked myself reading various iFixit forum posts, Amazon reviews and Reddit posts talking about how the screen glass would fall out of their iMac after applying the replacement adhesive tape.

Oh shi–

Drawing inspiration from a 27" iMac thread I decided to order some clear duct tape to use to fix the screen to the case, for extra protection against the adhesive tape failing.

My strip replacement kit (not from iFixit) arrived last day. I’ll need to look at it.

Before I do so, I’m waiting on the rest of the internal consumable parts to arrive before I learn just how good or bad the aftermarket adhesive is.

In lieu of buying adhesive tape, should the adhesive strips be insufficient, I do have a can of very sticky 3M-style spray adhesive (not 3M, but a certain Canadian brand available at your local Canadian Fire) handy, as adhesion at point of design contact seems a preferable (and, cosmetically, more subtle) fallback over using clear tape.

Pretty much this. I got this iMac for free from a childhood friend who I'd helped upgrade to an M1 iMac, and I'll be damned if I'll have to toss this out. If I was able to eke out ~1.5 year's worth of use as a daily driver running it entirely off of an external SSD, I know I can get many more years of use as a primary machine with 16 GB RAM and a new internal SSD.

THAT’S THE SPIRIT! :D

Likewise, this one (the 2.9 i5 variant) was given to me for free, for helping out a friend with long covid to get their place packed and ready for movers, just before they moved to be nearer to family out west. They had been using it, more or less, as a doorstop. (Their main rig was a Razer gaming desktop and, yes, they were a gamer.)

I thought about potentially caving and just getting an Apple Refurb iMac,

Noooo don’t you do iiiiiiittt

but I honestly don't see the point seeing as how this 2013 iMac meets pretty much all of my needs right now. It just needs some patience and a little elbow grease.

THA… :: oops, sorry… whispers :: that’s the spirit!
 
That gave me a much needed laugh. I might seek out the entire film. :)
It was a great film back when I was in middle school and Jim Carrey was all the rage. I still can't believe it spawned a prequel.

Some of the comments left by viewers are hilariously accurate about the direction that Apple has taken...

The amount of likes receives by each of those comments indicates that we're actually far from an isolated bunch on this subject
No joke, but as an interesting experiment (and part of my quest to find an affordable AlphaSmart replacement) I actually tried to daily drive one of those back in grad school - Smoorez has a really fascinating, extensive in-depth look at one of them here. The only difference was that mine had older specs and ran Windows CE.

Long story short, what actually hobbled it for me at the time was the software. Apart from enthusiasts trying to eke extra life out of their netbooks, there was practically zero software support for Windows CE on ARM; most of the software I found outside of forum hobbyists was for Windows CE on x86.

I simply couldn't use it as an effective writing machine because apart from WordPad there wasn't anything I could use for long-form writing. Well, that and the ridiculous keyboard. And the awkward trackpad button placement. And the low res screen. And the crazy huge display bezel...

By the Most Annoying Actor in the World, no less. Double Word Score!
I don't want to be a hater, but apart from his dramatic roles, I just find his comedy...really grating.

Oh yes. Craig. The B-minus grade audiophile brand of the ’70s which, by the 1980s, levelled off as the eminent C-minus grade brand of audio just beneath Realistic C-plus), just one step above… Audiovox and Yorx (bronx cheers). Buckle up, because now Craig is getting into… computing.

What could possibly go wrong…
Oh yes, what indeed! Oh, the places you'll go...

I actually used a Craig tablet when I was doing my B.Ed; I had the bright idea of putting all of the PDF versions of the Ontario curriculum documents on a tablet for easy reference. Well, it would have been a bright idea if I'd put all of those massive PDFs on a device which didn't use an 800 Mhz CPU and 256 MB of RAM...


Oh shi–
Yes, that's exactly what I said!


My strip replacement kit (not from iFixit) arrived last day. I’ll need to look at it.

Before I do so, I’m waiting on the rest of the internal consumable parts to arrive before I learn just how good or bad the aftermarket adhesive is.

In lieu of buying adhesive tape, should the adhesive strips be insufficient, I do have a can of very sticky 3M-style spray adhesive (not 3M, but a certain Canadian brand available at your local Canadian Fire) handy, as adhesion at point of design contact seems a preferable (and, cosmetically, more subtle) fallback over using clear tape.

If you want to jump down this rabbit hole, there's several posts out there complaining about the iFixit tape failing. And apparently the OWC tape isn't any better. And while the Amazon tape kits out there have a lot of good reviews, it seems like users who've used the tape for on longer have also reported adhesive failures.

From the MR thread, it seems like Apple OEM tape is the way to go for this repair. But that assumes you can find a trustworthy place on eBay to get them. And if you did, that tape is going to be 10 years old. Who knows if the adhesive is still going to be as strong as it should be? (eBay link: Mods - not my auction!)

That's what inspired me to use transparent duct tape as an additional measure to keep the screen on if (*gulp* when?) the adhesive fails. I used Gorilla Crystal Clear Tape. I was originally considering using the tesa Ultra Power Clear Super tape I saw in the 27" iMac thread, but apparently people on one of the iFixit threads are urging people to not use tesa tape as its adhesion power can crack the display.

Maybe I should order another set of adhesive tape, just in case. But I don't know if I should order it from iFixit again, or just throw caution to the winds and get a cheapo set from Amazon.

My main concern about using other adhesive solutions is that if you ever need to get back inside the machine, adhesive spray or glue might make it impossible...

Still. Good luck on your repair!


That episode of MST3K is still one of my favorites (right up there with the movie and the legendary episode for Overdrawn at the Memory Bank), and Idiot Control is just so...so fitting for this modern age of...everything. After my quest to deal with the tape issue, " 👌IT STINKS!" is the perfect response.

If you have it/can find it, The Final Sacrifice remains my all-time favorite. Canadian content!

THA… :: oops, sorry… whispers :: that’s the spirit!
I had a 2009 A1181 as my daily driver desktop Mac before getting this iMac, and I'm still joyfully using a 2010 11" MacBook Air I repaired and upgraded I recently got on the cheap from Facebook Marketplace. Early Intel Macs 4 Life!

Oh and to bring this back to the OP, after taking Terminal out of Developer Tools in the Security and Privacy prefpane, I haven't encountered anymore watchdogd kernel panics. But honestly, I've been so fed up with the crashes that I'm more than willing to nuke and pave my system with a clean install.

I honestly can't say if the fault for this lies entirely with Craig Federighi, but seeing consistent complaints about modern Mac OS X getting slower and slower (and now more bloated with AI!?) makes me long for the days of Bertrand Serlet and OS X 10.6. And I still remember the wonder I had when I upgraded my 1.4 Ghz MacBook Air from 10.7 to 10.9 and discovered my system actually ran faster than it did before.
 
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