iMAC keeps crashing

Hi,

Unfortunately for some time now, my 24" iMAC (Build 10K549) running MAC OS 10.6.8, has been crashing. I've posted to the Apple support forums without success so I was hoping to get some help here!?!

I can use it without problems for ages until I do something a little more intensive and BLAM! One particular set of steps which seems to trigger it is accessing the "show top sites" within the Safari browser; the "top sites" opens, I scroll up and down then KA-POW!

To cut a long story short I thought I had installed one too many applications and that something had got confused; I thought it was VMWARE Fusion. I've since formatted the hard drive and reinstalled MAC OS, but it keeps crashing!

I've booted the computer into the Apple Hardware Test mode and run the short and long tests successfully. I therefore don't think it's a hardware problem, but what else is there?

Can anyone help? I refuse to write of my beloved MAC.

Do you do anything hardware related recently...like installed more ram?

- Nick

No hardware changes

No. Absolutely no hardware changes. I've also booted into safe mode and run quite happily without seeing a crash!

I had wondered whether keeping it in the kitchen and using it there has done something? I'm thinking of opening it up and giving it a hoover!!! Does anyone know if dust could cause such effects???

Download the Mac SMART reporter and run the test. Let's see what it says about your hard drive.

Dixonj said:

No. Absolutely no hardware changes. I've also booted into safe mode and run quite happily without seeing a crash!

I had wondered whether keeping it in the kitchen and using it there has done something? I'm thinking of opening it up and giving it a hoover!!! Does anyone know if dust could cause such effects???

Click to expand...

If you have not made any hardware changes lately...and you can run in safe mode successfully...then my guess is you have some sort of software conflict causing the freezes.

God only knows what has been installed on the computer (by the user)...that could be causing the conflict. But if the freezes only started recently...then most likely something was installed recently causing conflicts.

And please let's go down the road of thinking that there is a virus of some sort...since that is very very unlikely on a Mac.

If you are adventuresome...one way to totally test if it is a software conflict is:

- take an external hard drive
- install an OS on it (same version as you have on the internal HD)
- boot the computer from the external HD
- use the computer as normal to see if it freezes

If no freezes...then there is almost definitely a software conflict of some sort on the internal HD.

HTH,

- Nick

And what type of crash?

The machine shuts down on it's own.
Everything freezes but you can still move the cursor around.
Everything freezes, including the cursor.
You have a kernel panic - that screen that pops up telling you to shut down the machine in multiple languages.

The crash is a complete loss of power / a halt! No freeze at all.

I've reinstalled MAC OS X and there isn't anything else installed. The crash still happens, so I'm not sure how it could be a software conflict!?!

I'm going to look at MAC Smart Reporter as suggested to hopefully start ruling out components.

Is anyone aware of any tools to monitor or test power?

Dixonj said:

The crash is a complete loss of power / a halt! No freeze at all.

Click to expand...

Maybe I misinterpreted your iMac's crashing as freezing.

So when you say your iMac is "crashing"/complete loss of power...are you saying that your computer completely shuts down...completely powers down randomly...display goes dark?

- Nick

First thing I'd look at if it's powering down on it's own would be the fans.

Download iStatPro or smcFanControl to check temps and fan speed.

If the OP really means that it completely loses power, then the problem could be that his power supply is dying when it gets taxed at all. This was a common problem on some iMac models, though I don't recall if the Intel 24" was one of them.

It could be overheating but given his original description I'd say the power supply is starting to go.

Another vote for dodgy power supply.

I have the 20" version of your 24". I have had that happen and I had to reset the SMC. Mine was doing that same thing and shutting down all of a sudden and this solved it completely. When the issue happened it was like someone pulled the plug from the wall. Give it a try.

Resetting the SMC for Mac Pro, Intel-based iMac, Intel-based Mac mini, or Intel-based Xserve

Shut down the computer.
Unplug the computer's power cord.
Wait fifteen seconds.
Attach the computer's power cord.
Wait five seconds, then press the power button to turn on the computer.