24" IMac Error

Hi,

My 24" IMac 3.06 is the 2008 model and had been running without any faults for the last 2 years. I noticed a few days a go the screen went a bit crazy and moving the mouse cursor made it worse like a GFX problem so I restarted it and it was fine.
Saturday morning I checked the IMac and the screen saver had frozen during the night and it wasn't responding, so I restarted it. On the grey start up screen before the apple logo was lots of little yellow wiggles, like vvvv or wwww all over the screen. On restart the apple logo appears you hear the bing noise etc, but after a while it gives me the multi language warning saying my mac needs to be restarted. (Kernel Panic?) So I did this lots of times but it keeps giving this error.
I found my Apple Hardware Test DVD and restarted the mac holding the "D" key on the keyboard but it won't start the AHT. I've tried it lots of times, Pressing either "D" or "C" but nothing happens it just continues on to the multi language error.
I removed my 2x2gb ram and tried them one at a time, but that made no difference. I also tried unplugging the mac and holding the power button down for 5 secs but still it shows this error screen.

Any ideas what I should try next? I am on Snow Leopard

Cheers!

Sounds like you have done a lot of nice troubleshooting:

- kernel panic?...yes that sounds like the problem (usually due to something wrong with the hardware)
- tried swapping the ram one at a time...great idea!
- tried booting from the Hardware Test DVD...Awesome Idea!

Just for the heck of it...you could try:

- resetting the SMC:

Intel-based Macs: Resetting the System Management Controller (SMC)

- reset the PRAM:

Resetting your Mac's PRAM and NVRAM

- try booting from any other OS CD/DVD you have (like the gray disk you got with your iMac, not the Hardware Test Disk)

If none of this helps...and from the info mentioned so far. Here would be my initial guess's as to the problem:

- both ram modules went bad at the exact same time (very unlikely)
- your optical drive is bad (if you are unable to boot from any CD/DVD)
- your logic board has gone bad in some way (worst case scenario, let's hope not)

HTH,

- Nick

Tried SMC 5 second power button reset. Made no difference.

Tried PRAM reset, Command-Option-P-R keys after power on, but nothing happens the Mac does not restart again as it should?

NVRAM test only for PPC cpu?

My Grey install disc that came with the IMac says press "C" to install or "D" for AHT neither of these work. DVD will eject if you restart while holding down mouse buttons.

Think its starting to look bad...................

JMac79 said:

Tried SMC 5 second power button reset. Made no difference.

Tried PRAM reset, Command-Option-P-R keys after power on, but nothing happens the Mac does not restart again as it should?

NVRAM test only for PPC cpu?

My Grey install disc that came with the IMac says press "C" to install or "D" for AHT neither of these work. DVD will eject if you restart while holding down mouse buttons.

Think its starting to look bad...................

Click to expand...

On the positive side...the problem could be your optical drive is bad. Or the initial problems could be a bad hard drive. Either of these would not be too terrible. But you cannot properly troubleshoot the hard drive without the optical drive working properly.

On the not so positive side...if it's the logic board...that would be a very expensive repair...and if you had anything older than a 2008 iMac...I would almost say time for a new computer.

Also...can I/we assume there is no warranty/Applecare left on this computer?

- Nick

Sadly no apple care/warranty left as I've had it approx 2 years and that only lasted 1 year as far as I know.

So, would it Kernel Panic with no DVD or HDD attached? Just as a method to narrow it down.

Also does the yellow wiggles on the grey screen mean anything? I can't imagine its a good thing.

JMac79 said:

Sadly no apple care/warranty left as I've had it approx 2 years and that only lasted 1 year as far as I know.

So, would it Kernel Panic with no DVD or HDD attached? Just as a method to narrow it down.

Also does the yellow wiggles on the grey screen mean anything? I can't imagine its a good thing.

Click to expand...

Yeah...I only asked about the Applecare just in case you might have purchased the extended 3 year plan.

As far as the kernel panic. Many times kernel panics are hardware related...and many many times it's due to bad ram, incompatible ram, or poorly seated ram. But since you already checked the ram...that does not seem to be the issue.

To be honest...normally I would not expect to get a kernel panic from a bad hard drive or optical drive (CD/DVD drive)...but I don't want to say 100% that it can't happen.

Since you're having video problems on a Macintosh (iMac)...where there really is nothing a user can do to repair or replace the graphics hardware (since it's soldered onto the logic board)...you could be getting a kernel panic from the bad video hardware (or something else that has gone bad on the motherboard)...and is effecting the video. If this is the case...unfortunately it's a very expensive thing to repair.

As far as the optical drive not reading disks. If you're like me...you hardly use your optical drive. If this is the case...maybe for some weird reason your optical drive went bad a while ago. Now that you have the video problem (and want to run the hardware test program from the disk) because of the video issue...now instead of one problem (video)...you actually have two problems (bad video & bad optical drive).

You might be getting closer & closer to needing to simply take this computer to your nearest Apple Store, having them look at it, and paying the service fee they charge...and possibly have Apple do the repair. Or after Apple tells you what's wrong...you can get the parts you need & do the repair yourself.

I think that your computer is still new enough that it may be worth it to have Apple troubleshoot it (and pay their fees). On an older computer (older than yours) it may not be worth it as much...because of the lower resale value of the computer.

These are all just theories of course...just trying to make sense of what's happening with the symptoms & troubleshooting steps mentioned.

- Nick

son sakereb

Thanks Nick, It looks like I'll have to get Apple to have a look.

Thanks for your help.

It really does sound bad and you have done some excellent troubleshooting.

Only thing I have seen is if the Hard Drive really messes up with some iMacs, it will not boot from a DVD or even a Firewire external drive. Had a 24" I fixed for a buddie do that. Thought it was his Logicboard but it was the hard drive causing it. Worth a try. Is yours the White 24" or the Metal one?

What sounds bad though to me is the yellow triangles all over the screen. Almost sounds like the graphics Chipset messed up.

Do keep us posted.

Its the early 2008 Alu model, 3.06 cpu with 512mb gfx, the top spec model at the time

And yes the little yellow wiggles are a bit scary, though after the apple logo disappears the screen fills a dark grey colour from top to bottom and the multi language "restart your mac" etc message appears the yellow wiggles have gone and the screen looks normal. (Apart from the error message!)

I may try to swap out the HDD as a test, since your reply gives me some slim hope. Whats the worst that can happen?

worst that can happen? If you do it carefully nothing bad. Either it will still have the issue or stop getting the KP and boot from the DVD.

All I know is I have seen 2 iMacs have issues when the HDD went bad. One would not even boot with anything past the beginning white screen. Yours is different but it's can't hurt to try it without the drive. Just be careful taking it apart. The Alu models are very different. There are take apart guides all over the net. iFixit should have one.