Author Topic: iMac problems.  (Read 1024 times)

iMac problems.
« on: November 06, 2018, 08:19:41 pm »
My father has an Imac, it's newer than mine,  late 2009.     It's got a problem , it boots up & gives a password prompt, but as soon as you move the mouse or try to enter anything with the keyboard it crashes (or so I'm told, not been able to see it yet).  Hence it's unusable.


Can anyone suggest what is causing this & how it might be fixed ?
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Re: iMac problems.
« Reply #1 on: November 06, 2018, 08:28:02 pm »
Dunt know.  I fixed my blueberry iMAc - which would nto boot - by putting the hard drive in a freezer bag and freezing it overnight.
This deals with 'stiction'of the drive heads.

In your case I would suspect the RAM. Take the top off. Now reseat the RAM.
As an experienced IT engineer, I can tell you that is a posh word for - take the RAM stick out of its slot and replace it.
Do this after you have grounded yourself, or use a static strap.
The reasoning here is that any dody or dirty contacts on the RAM module will be cleaned by removing it and replacing it in the slot.

Re: iMac problems.
« Reply #2 on: November 06, 2018, 08:42:41 pm »
0800 048 0408

Give this number a call. It's Apple support.

They sorted out a log-in password-not-recognised problem on my 2015 iMac when I installed OS Mojave last Saturday.

Gattopardo

  • Lord of the sith
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Re: iMac problems.
« Reply #3 on: November 06, 2018, 09:03:36 pm »

Jaded

  • The Codfather
  • Formerly known as Jaded
Re: iMac problems.
« Reply #4 on: November 06, 2018, 09:07:09 pm »
First - the file system:

Try going into Single User mode and typing the two lines that appear at the end of a long screen of text.

Reboot
Hold CMD +S until text appears running up the screen.

When the text stops there are things to type

(The first one looks like /sbin/ fsck etc.) File System Check
When it has run through see if it says the file system was OK or it was modified
If it was modified, type the command in again.

Then do the next line (which includes mount)

That one doesn’t take long. When it has finished type ‘exit’ to reboot the machine.

Then the thing you can try is resetting the PRAM.

Reboot the machine and immediately hold down CMD Option P R all at the same time. It’sworth Practising this before rebooting - requires lots of fingers. Then hold them down until the third reboot ‘bong’, and let the machine reboot normally.

PRAM holds a number of settings in  a non-volatile ram, and these can get corrupted.

If those two steps didn’t work, report back here!
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Re: iMac problems.
« Reply #5 on: November 06, 2018, 09:10:44 pm »
You can try booting it in verbose mode and seeing if you spot any interesting error messages:

https://support.apple.com/en-gb/HT201573

You can also try running hardware test:

https://support.apple.com/en-gb/HT201257

Re: iMac problems.
« Reply #6 on: November 09, 2018, 10:31:31 pm »
Well I went around for the old gits 85th birthday & had a look.   (wine had been taken, so it wasn't a thorough check)


It boots up & gives you a password prompt but if you try to put a password in it wouldn't take the letters & you just got the spinning beachball.


Going into single user mode as recommended by Jaded worked, I got a load of diagnostics, File System Check said it had been modified.  I ran this again and then rebooted , this time it let me input the password ,  but still gave me the spinning ball.


Holding down the Alt key on startup took me to the disk health utility,  I used the first aid option to look at the drive , but it's still the same result.


He's not got a backup , but barring his porn collection I doubt there's anything irreplaceable on there.  What next ?   (my 2008  machine has been totally reliable, so Ive never had to get don & dirty with it)
Not fast & rarely furious

tweeting occasional in(s)anities as andrewxclark

Jaded

  • The Codfather
  • Formerly known as Jaded
Re: iMac problems.
« Reply #7 on: November 10, 2018, 12:15:54 am »
Ok.

There’s still try the reset PRAM, and there is the next step I’d use which is to see if you can connect it to another machine (yours?) as a slave drive. If you can you then can try some disk tender care and attention, or, at the very least, take the porn collection off it before wiping it.

To connect it to another machine as a slave drive you need:

an appropriate cable to connect the two machines.
the ability to put the troublesome machine into Target Mode. Usually by holding down the T key during startup until there is a FireWire symbol on screen.

If you can do these, then you can run Disk Utility on  the host machine, to look at the slave machine. It’s pretty much what you’ve done with Single User though. You can also access all the data on the slave machine, which might be more important.
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Re: iMac problems.
« Reply #8 on: November 10, 2018, 01:50:22 pm »
I don't know what he's done , but he's emailed to say it just started working again.  Thanks for all the advice.
Not fast & rarely furious

tweeting occasional in(s)anities as andrewxclark

Jaded

  • The Codfather
  • Formerly known as Jaded
Re: iMac problems.
« Reply #9 on: November 10, 2018, 02:06:35 pm »
It is possible the fsck and disk utility fixed it and it’s taken a little while to re-sort itself.
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Re: iMac problems.
« Reply #10 on: November 11, 2018, 05:36:50 pm »
And its gone again, boots up, accepts the password, spins for a while then goes to a blank screen ?
Not fast & rarely furious

tweeting occasional in(s)anities as andrewxclark

Jaded

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  • Formerly known as Jaded
Re: iMac problems.
« Reply #11 on: November 11, 2018, 06:12:27 pm »
Did you try resetting the PRAM?

it is either hardware or software (!) it's about eliminating the most likely causes to narrow down the cause

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Re: iMac problems.
« Reply #12 on: November 11, 2018, 06:33:10 pm »
Yes, he’s already tried that & so have I.  I’ve got a spare drive in an external caddy at home . I think I’ll load a fresh iOS on that & try to boot up from that & see if we can rescue anything off the built in drive before nuking it & starting from scratch.
Not fast & rarely furious

tweeting occasional in(s)anities as andrewxclark

Jaded

  • The Codfather
  • Formerly known as Jaded
Re: iMac problems.
« Reply #13 on: November 11, 2018, 06:55:03 pm »
Yes, booting from a spare drive should help eliminate os/filesystem errors.

To rescue stuff from the old drive you may have to deal with Permissions.

If you are gong to nuke (and replace the drive) it is worth seeing about an SSD instead of an HD - much, much faster with newer OS's
If you don't like your democracy, vote against it.

Kim

  • Timelord
Re: iMac problems.
« Reply #14 on: November 11, 2018, 07:00:45 pm »
If you are gong to nuke (and replace the drive) it is worth seeing about an SSD instead of an HD - much, much faster with newer OS's

But not until you know it's not some other hardware problem.
Careful, Kim. Your sarcasm's showing...

Re: iMac problems.
« Reply #15 on: November 11, 2018, 07:07:25 pm »
If you are gong to nuke (and replace the drive) it is worth seeing about an SSD instead of an HD - much, much faster with newer OS's

But not until you know it's not some other hardware problem.


Yes, I did that with my 2008 model last year,  I believe it's slightly fiddlier with the 2009.  Not buying any new hardware until it's been running properly for a while.
Not fast & rarely furious

tweeting occasional in(s)anities as andrewxclark

vorsprung

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Re: iMac problems.
« Reply #16 on: November 12, 2018, 10:32:38 am »
I have an old iMac you can have

Ah, hang on.  I checked the history book ( https://en.wikipedia.org/wiki/IMac ) and the one I have is a iMac G3

Whereas you probably have a completely different model
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Re: iMac problems.
« Reply #17 on: November 12, 2018, 12:56:18 pm »
He's got 2 older Mac towers stuck under a desk & a Mac mini as well.   My parents don't believe in throwing stuff away.  There is a box somewhere with WordStar on 5/14" inch floppies  :facepalm:
Not fast & rarely furious

tweeting occasional in(s)anities as andrewxclark

Kim

  • Timelord
Re: iMac problems.
« Reply #18 on: November 12, 2018, 02:11:42 pm »
Thing about WordStar is that it worked.
Careful, Kim. Your sarcasm's showing...

Gattopardo

  • Lord of the sith
  • Overseaing the building of the death star
Re: iMac problems.
« Reply #19 on: November 13, 2018, 02:46:43 pm »
He's got 2 older Mac towers stuck under a desk & a Mac mini as well.   My parents don't believe in throwing stuff away.  There is a box somewhere with WordStar on 5/14" inch floppies  :facepalm:

That is your digital inheritance ;)