'Restart your computer' message


East Anglia branch
Has any one else had this since installing Tiger?

I can be doing anything on the computer when, for some reason, the screen dims (just like in Dashboard), and an official looking message appears on screen reading:

"You need to restart the computer. Hold down the Power button for several seconds or press the Restart button."

At the same time, I am unable to do anything else - either a mouse click, or obtain a screenshot by using a keyboard combination. The clock at the top of the screen also freezes.

The message is in four languages, and can appear at any time, no matter what I've been doing - browsing the Web, trying to configure widgets in Dashboard, or anything else.

This has happened several times now. I am avoiding using the Dashboard now, just in case it's a glitch connected with this, although it just happened a few minutes ago as I was surfing.

Does anyone know what is happening?
Sounds like a kernal panic. Congratulations, you've crashed the uncrashable system :D .

It shouldn't related to dashboard, I don't think. It usually means that something is wrong with your Mac (be it hardware or software).

The most common experiences I've had with KPs were a result of either faulty RAM or bluetooth screwing things up. But on the other hand, OS X might need repairing or a reinstall.
yup. that is a kernal panic. in plain english, a very hard crash. best to do what it says. i've had maybe three since owning this mac
I've only had those when I was screwing with a DWL-120 Wireless Adapter with my eMac in Panther. Never had one in Tiger. (knocks on wood) Have you intalled any new hardware lately?
No new hardware - just Tiger.

What's the solution? - as this seems definitely related to installing the new OS - would it be worth reinstalling?

What else can I do? - is it worth considering upgrading the machine - more RAM, new hard drive, etc - could it be that the machine's spec is just not up to handling Tiger? As you can see, the spec is fairly low by today's standards.

Is it safe to keep on using it?
From the specs in your signature, you're really pushing your system. The most likely source to your problem is your hard drive as I see it. You have a 13 GB disk, and you need to keep at least a few GBs free for virtual memory (aka swap), especially since you're low on real memory (256 MB RAM is just within the requirements).

If you run out of disk space, you'll have no more room for virtual memory, and that can cause a crash.

The computer you have is just barely capable of handling 10.4, my suggestion is that you upgrade to a new computer. Considering what you have, I'd suggest a Mac mini. I bought one of those last week, and it's a really priceworthy 'puter. If you're strapped for cash, second best option is get a new hard drive and some RAM, and the third option is to just buy a new hard drive.

Then you need to be booting from the new drive, with the bigger disk, since the operating system will automatically store the swap files on the boot disk. You could move the swap to another disk of course, but that's pretty irksome, and the setting doesn't survive a system upgrade. You'd need to move the swap every time you update your system.
Getting more memory is definitely a priority for you. It'll speed up your machine.

As for the kernel panics, my flat panel iMac is doing that running 10.4.0 and it won't let me upgrade to .1. My other machines are not crashing with 10.4.1.
It's possible you (and I) have corrupted system files.

Ever since upgrading my iBook G4 1.2 14" to 10.4.1 I have had three kernal panics, all when opening the lid from sleep. Previous to this I haven't had any with any version of OSX. I'm hoping 10.4.2 sorts it out.
Are you using any software which is in beta? Or still first official release? It may be that, was the case for me.
No Beta software afaik, Convert.

Thank you all for your very practical suggestions to this problem, especially to elander and trickey.

Looks like (one way or another) I'm going to have to part with some cash!
Before you part with your money, be sure to do the following:

1. Back up your NECESARY data someway; I suggest an external HD, etc.

2. Boot up with the Tiger Install CD and run the disk repair program (From the Disk Utility on the CD), and then repair permissions.

3. Install Tiger by selecting the "Erase and Install" option.

4. Customize the installation by deselecting the extra languages option (not including your native language of course), and deselect to install every printer driver. Just install the printer driver set you need, or none at all. Doing these two things will free up a couple gigabytes of space, giving you more virtual memory.

5. Install and restart.

6. Repair permissions and let Spotlight do all it's indexing.

7. Restart.

It seems like a lot, but personally I would rather do that than spend my hard earned cash. In fact, I have done this not to spend cash :p
I love my graphite iMac DV! It's running panther at the moment, no problems. But we upgraded the hd a while back and have 640 megs of ram.

I think a mini as an upgrade would be expensive for you since your present monitor is built-in (you are not just switching out the cpu). And even if you did get a mini, the iMac is probably worth more to you than to anyone else, so you'd want to keep it running and have to buy a new a keyboard/mouse too.

Definitely try Qion's advice first, then - Ram is cheap, stuff some new memory in there.

You need to keep 10 - 15% of your disksize free for swap space. It may be that for you need more - 2 gig seems small for swap. A bigger hd would serve well.
My G5 suffered the same problems with 10.4 (problems gone since upgrading to 10.4.1)

You'll notice there's no problem with lack of RAM or HD space! ;)

I put it down to Tiger!
Did anyone suggest using Single user start-up with FSCK and then DiscWarrior or TechToolPro to fix the system and the volume, before doing such drastic fixes?
At which point does the system crash? during boot or random spots?
First thing I would try is getting a new memory stick.
Back in the 10.2 -> 10.3 days, I've had memory that worked in 10.2, but crashed when used under 10.3. Guess it just falls out of spec with the newer OS.
My system fails, and I mean fails, after using sherlock. cmd-f to find, and boom.

I called apple, I had reset the nvram, I had zapped the pram, I had cleared the cache with system optimizer x, I had reset permissions, i had used disk utility to fix disc. Nothing.

They told me to reinstall the os, but I had already done that too. I still have the problem

Also, this occurs with 10.4

mac 2g twin with 2.5g of ram on 10.3.9 with all firmware updates in place.
this was happening a lot to my machine too.

i set up a new user to see whether it would still happen - and i had no problems in that new user.

so i logged back into my main user - dragged my entire preferences folders (user/library/preferences) to the desktop - and restarted my machine.

yep - it meant a lot of re-setting up of certain apps (no biggie only takes a few moments with most, and the majority of apps actually dont need any setting up and just create a brand new prefs file.)

but - it also stopped the hangs and crashes and everything ran a whole lot better.

i kept the original preferences folder for a few days on my desktop just to make sure that if i needed it it was still there - but after a while of stable and happy use i trashed it.
I had this problem with my iMac G5 running 10.3.9, and it got so bad the machine wouldn't boot. I took it in and they replaced the midplane assembly. Took care of it. Don't really know what that is, but it's worked fine every since.
I had this dimmed screen sometimes on my ibook 10.3.x., when it waked up from sleep mode, when the modem was plugged in.

Had it now the first time on my g5 10.4.1.
This time the reason is an 3 year old self burned picture cd-rom.

so, check your periphery and disks.
there is hardware test on install disk to find broken ram.

good look