"Everything Apple"? iMac issues

[wgscott]

This may be off-topic (sorry), but since "everything apple" is in the forum title, I shall ask for your indulgence.

 

I have a 2013 iMac that lately (today) developed a repeated habit of powering off, seemingly at random.  The only way i can reboot it is if I wait about 10 or 15 minutes, pull the power cord out, and then plug it back in.  Only then can I power it on.

 

In a desperate attempt to convince myself it might be a software issue, I "upgraded" it to the high Sierra public beta #1 (which is dog-slow btw).  The issue persists.  It doesn't seem to correlate with anything (high CPU, etc) and for some reason didn't happen during the upgrade (which includes a file system reformatting).  

 

I'm guessing a faulty power supply or thermal sensor, but I have no idea.

 

Any suggestions?

 

 

[wgscott]

I zapped the PRAM and then it wouldn't boot until I reinstalled from the recovery partition.  The problem, if anything, has gotten worse.  I think it is  time to take it to the Moron Bar.

[wgscott]

2 hours ago, flatmap said:

I had an older iMac which also developed this problem.  I took it in and they diagnosed power supply was at fault. YMMV, of course.

 

I'm guessing it is this.  Oddly, I can compile stuff and make huge demands on the processors, remotely, but it seems to power off when I do something like click a tab in Safari.

[wgscott]

2 hours ago, Ralf11 said:

time for an Imac Pro?

 

Only if someone else pays.

[wgscott]

3 hours ago, rickca said:

I hadn't heard that one before.  I like it.

 

By that I mean sometimes they seem to know even less than I do.

[wgscott]

I think I will do this to try to make this go smoothly:

 

http://osxdaily.com/2014/07/29/sysdiagnose-mac-os-x-command/

 

[wgscott]

To starve the beast is my destiny.

[wgscott]

6 hours ago, Bob Stern said:

 

I think Chris should rename this forum to be just iTunes, not "everything Apple", consistent with the scope of Kirk's original forum.  I think the Software forum is more appropriate for non-iTunes issues.  

 

Well, this is admittedly off-topic.  I think if it were only iTunes, a lot of us might not pay attention, if we use other player software.  

 

6 hours ago, Bob Stern said:

 

That seems to rule out temperature issues, but if you want to investigate that anyway, try:

https://www.crystalidea.com/macs-fan-control

 

Is it just Safari?  I get kernel panics from time to time in Safari.

 

 

 

Thanks for the link.  I will give it a try.  No, the shutoffs are random, and they are not kernel panics.  It is as if someone pulled the cord.  No trace in any log files or crash reports.  The extended hardware tests, and disk check, all report that there are no apparent hardware issues.  Again, I suspect it is the power supply.  Given our third-world electrical supply, it wouldn't surprise me...

 

Looks ok:

 

[wgscott]

Well, as I was packing it up this morning to take it in, I saw the power cable had been chewed -- puppy teeth marks.  But it isn't clear to me she got down to the wire, and it must have been well over a year ago, but in any case I am trying with a different cable, just in case.

 

#CablesMatter

 

 

[wgscott]

I pulled it apart to see if she managed to penetrate the insulation.  I cannot see any evidence that she did, but since I switched cables, no shutdowns (yet).  Plus she has had her adult teeth more than a year.  I am unconvinced.

[wgscott]

13 minutes ago, Ralf11 said:

pics of the perp?

 

If you insist ...

 

 

 

 

 

[wgscott]

Ours look quite similar.

 

 

[wgscott]

Mine is 55 lbs (fully grown female).

 

BTW, it wasn't that power cord.

 

#PowerCablesDon'tMatter  #RedHerrings

[wgscott]

This 37 page thread on the Apple Support forum has lead me to believe this might be a significant problem ...

 

I took it to a 3rd party Apple-approved repair place, and basically he asked me the year and make and so on, and then recoiled, saying it was a known issue and that it could be the power supply, the fusion drive, the logic board, etc. or none of the above (consistent with that 37 page thread).  He didn't want my money.  He just wanted that computer out of his shop.  I can't say I blame him.  This seems to be a widespread issue.

 

I made (another) appointment with Apple for Sunday.  If they will replace the power supply for some reasonably sane amount of money, then I will do it, but I am not going to pay for a new mother board on a computer almost 5 years old.  The glare from the screen alone makes me not want to put any more money in it.  

 

Oh, and if you want to DIY, you have to cut the glue that holds the glass display to the chasis with a little pizza cutter-like tool.  WTF is wrong with Apple?

[wgscott]

12 minutes ago, 4est said:

Hey Bill,

 

Have you tried cleaning out the dust in your iMac? There is a hidden intake behind where the mounting bracket attaches to the body. I lost mine from over heating due to this. Upon opening it up, I was amazed by how much dust was inside despite occasionally blowing canned air in reverse through the innards.

 

Funny you should mention that.  Every time I move the thing it rains a pile of dust, and I was thinking I should get in there and clean it out with some compressed air (which I squandered cleaning my bike, so I have to go get it).  I haven't seen any direct evidence of overheating, but as you say, it has all the hallmarks.  Thanks for posting that suggestion!

 

Quote

I am resisting the temptation to post a pic of my Belgian Sheepdogs or Sophie, the Golden I lost to my ex.

 

Post away.

[wgscott]

9 minutes ago, 4est said:

 

Open it up if you can. There are multiple fans. My culprit was the air intake under the mount that I never even knew existed until I flipped it onto a table. The intake was completely filmed with a layer of dust. I doubt much air could get through, and the canned air didn't work from the exhaust slot - too many paths and not enough force to displace the film. At least take a look at that one. Cleaning that alone would have saved mine methinks. I think I lost my SATA controller, or at least it acted as such.

 

I just vacuumed the intake.  Where is the exhaust slot?  Was yours a 2012?  I have to cut a glue seal, so I am a bit nervous, and don't have the right tool.  If I open it up, I might as well DIY replace the power supply.

 

Edit:  I found it -- all along the bottom edge of the chassis.

[wgscott]

3 minutes ago, 4est said:

2011 as I recall. Mine had an exhaust slot along the upper rear/back, and intakes at the perforated bottom AND a 30-40mm round grate underneath where the stand mounts to the body. The latter is what screwed me.

 

I have the fan cranked all the way up now, and there is definitely air being blown OUT from the (square) grate underneath where the stand mounts to the body, so maybe  it sucks air in from the bottom slots on mine?  I must vacuumed the bajeezus out of both, fwiw.  But every computer I have ever cracked open has been caked with dust.

 

Current temps:

 

 

[wgscott]

9 hours ago, Bob Stern said:

A spudger tool usually is recommended to pry open the case.

 

I've found that the spudgers sold by SpudgerToolCom are more durable than those sold by iFixIt.

 

https://www.amazon.com/gp/product/B00DRFD0GG

 

(Also useful for prying off dashboard trim of your car.)

 

I think it might be a little bit more involved than that:

 

https://eshop.macsales.com/item/OWC/DIYIMACGEN/

 

Quote

Note: For 2012 and later models, before attempting to perform this installation, please watch the OWC Install Videoin its entirety to determine your ability to perform this complex upgrade. OWC assumes no responsibility for damage that may occur during the install. Technical support for this DIY product consists only of the OWC Install Video.

 

[wgscott]

On 7/2/2017 at 1:39 AM, Bob Stern said:

 

That seems to rule out temperature issues, but if you want to investigate that anyway, try:

https://www.crystalidea.com/macs-fan-control

 

Is it just Safari?  I get kernel panics from time to time in Safari.

 

 

 

I downloaded the fan control app and set it to read the temperature from the GPU PECI and crank when it gets warm.  So far, I haven't had a power shut-off since I did this (and vacuumed the air intake and exhaust ports).  So maybe it does have something to do with over-heating.  

[wgscott]

29 minutes ago, elcorso said:

 

More reason to clean the inside of your iMac. Most of the time even the fan blades are dirty...

 

We want it opened. And inside pictures, of course  

 

Roch

 

I've opened up Mac mini and Macbook air, and (trivially) power-macs.  But the idea of using a pizza cutter to slice the glue that holds the glass and LCD onto the chassis is not something I feel like doing.  I would rather pay someone competent not to fuck it up.  I do most of my own bike wrenching, including hubs and bottom-brackets.  But there are some things I won't do, like wheel building.  A man's got to know his limitations.

 

 

[wgscott]

23 minutes ago, AudioDoctor said:

I hope not, there are plenty of other specialties that need surgeons as well.  However, if you want it done well that may be your best option.

 

Funny, I don't think that would have bothered me.  I quite enjoyed gross anatomy.

 

Two places have turned me down for doing the power supply transplant -- I want to try a different brand, LiteOn, instead of what Apple has been using (Delta).  So I may yet have to do the surgery myself.  

 

At least if you are a pediatric neurosurgeon, no one holds you personally responsible if you accidently sever a nerve or two.