advertisement


iMac problem.

Andrewxyz

pfm Member
My home desktop is a late 2008 iMac with a 3rd party SSD running El Capitan.
Yesterday it froze, then began to reboot constantly. Notes refer to a kernel panic.


I’ve tried resetting PRAM & SMC. Neither had any effect.
Rebooting while holding R should put me into recovery mode, but doesn’t work.
Rebooting holding the Alt key gives the option of booting from the SSD, the recovery drive or Time Machine .
Neither Recovery drive or Time Machine seem to do anything.

I was able to start in Safe mode, this was very slow & kept redrawing the screen. I was able to get Disk Utility in First Aid mode to Repair the SSD, but it’s had no effect. I was also able to use Migration Assistant to restore from Time Machine, but the only version offered was after the problem started. I did this & it remained stable during the process, but when it finished just began to reboot again.

What other steps does the panel suggest? I have the original Snow Leopard disk here. Can I boot from that & then try restoring from Time Machine again?

It’s tempting to just order a new one, but I wanted to hang on until the rumoured bigger screen is launched in the next few months.
 
P.s. I think doing the snow leopard thing in R mode will get you running and it’ll update to the latest usable OS. Then erase your SSD with disk utility then SuperDuper your recovery disk over to the erased SSD. Only use Time Machine sparingly or you just import the fault again - is what I think I remember but CHECK with someone who knows what they’re doing before you burn bridges.
 
First I would like to find out whether this may be a hardware issue. So what I would do first is plug an external HDD or SSD into a USB port and then install SL on that. Then boot SL from the USB drive (it'll be slooooow) and see if the machine becomes stable. If it is stable then install SL on the internal disk after erasing it <- thats an important step! Then boot SL and see if its now stable.

You can then download the El Cap installer and migrate your internal SSD. Check for stability.

Once you have a stable machine you can copy across things you need from your Time Machine backup. Don't use migration assistant as has been pointed out you may be bringing trouble back.

Fingers crossed,

DV
 
I booted into Safe mode (shift key) held down & it prompted me for login details , I now seem to have a fully working system again, not the stripped down version I was led to expect.

Everything has been stable for approx 30 minutes. I'm quite reluctant to do another restart now .....
 
Some info from Apple on Safe Mode:-

If the issue doesn't continue in safe mode
If the issue doesn't continue while in safe mode, leave safe mode by restarting your Mac normally. Then test for the issue again. The issue might be resolved.

If the issue returns after leaving safe mode, startup items are probably at fault. Apps can install such items in numerous places, and they aren't always easy to find or recognize. For that reason, you should first make sure that you've installed any available updates for your Apple software and third-party apps.

If updating your software doesn't help, try any of these solutions:

  • Test your login items.
  • To learn whether software in your user account is causing the issue, set up a new user account, then log in to it and try to reproduce the issue in that account.
  • Unplug all accessories from your Mac, including printers, drives, USB hubs, and other nonessential devices. You could have an issue with one or more of those devices or their cables.
  • Reinstall macOS.
 
It rebooted a few minutes after my last post. It seems to be running quite hot & I can't recall hearing the fans recently.
I left it 30 minutes, cleaned the vents at the bottom & then it booted OK. Just installed Mac Fan Control & manually ran the fans at max for a couple of minutes, so they are still working.
 
It's now running for approx 30 mins + then reboots. I ran Apple Hardware Test using the original install disk from 2008 & it gives error code 4MOT/1/40000003:hdd-144 . I think this is a Fan problem, they are not running unless I manually turn them on using the fan utility. I reattached the temperature sensor when I installed the SSD several years ago. Might see if I can take the front off & give it a bit of an internal clean.

It's not worth spending money on but I'd rather not replace it until I see what's available at the next launch event.

If anyone is looking for a new IMac then Costco seen the cheapest place at the moment. About £150 cheaper than Apple for most builds and with a better choice than John Lewis, who don't offer models with more than 8G of memory.
 
After running well all weekend it’s now knackered again. Latest rumours suggest the large screen version may not be launched until the middle of the year so I’ll go for a 24” one.
Costco do 16G/512G for £1700 with a 2 year warranty, but only have it in yellow, orange or purple! Decisions, decisions…
 
Is it still a fan problem? If it is then before you decide to reprogram your iMac with a very large axe it may be worth trying once again an SMC reset. I know you say that you have already done that but things have happened since and its the SMC that controls the fans. The most heat will be generated by the CPU and GPU and each will have its own temperature sensor.

Do you actually need an iMac? A s/h Mac Mini and nice VDU may suffice until Apple releases the larger iMac that you want.

Cheers,

DV
 
I did an SMC reset earlier, along with the other usual stuff. It's now working again, and I've used the fan utility to keep the HDD & CPU fans running at a constant low rate.

My ideal solution would be a nicely specced M1 Mini and a currently non-existent Apple branded Retina monitor, something else that is rumoured to be in their pipeline. As the current iMacs seem basically unrepairable I'm no longer too keen on the all in one approach. Choosing a 3rd party monitor seems a bit of a minefield.

I don't do anything too demanding, mostly browsing & some very occasional photo editing. However I don't have a TV so use the current iMac for watching downloaded videos & DVD's as well. (I've got an unused Apple Superdrive which will hopefully work using a USB C-A adaptor).
 


advertisement


Back
Top