[Octo]

I have a Intel based Mac Mini which has started to act up. If I get it to boot into Mac OS X it will either freeze or go into a constant reboot loop giving me the boot chime every 5 seconds. I swapped back in the original memory and tried to perform a PMU reset (or Intel equivalent) and the system does not behave any better. When I try to boot from DVD I get a message indicating that the system needs to reboot. If I boot a DVD that has the hardware test, it either passes or it freezes and fails to finish the test.

I eventually booted a Linux based system and got two similar messages "NMI received for unknown reason XX on CPU 0. Do you have a strange power saving mode enabled? Dazed and confused, but trying to continue", XX was either 2d or 3d.

Is there an extended hardware test available for Intel base Macs that might do a better job of detecting my problem, otherwise I guess I'll install linux onto this Mac Mini and see how stable it is.

[AKcrab]

Does it freeze at the same point in the hardware test?

A service provider will have an extended test, but you would have to pay them to diagnose.

This smells like a failed logic board to me.

[Waragainstsleep]

And to me I'm afraid.

[Octo]

If I run the standard test it seems to pass, but if I check the box for the extended test, it freezes part way through. I haven't seen a pattern that it always freezes at the same place.

[Waragainstsleep]

You need to ask Apple what the difference is between the standard and extended tests. You are better off calling Applecare than going in store for this. Whoever answers your question will need to speak with one of the uber-techs. A regular Applecare guy and even tier two are unlikely to know this info for certain. If they don't escalate the question for you, don't trust the answer you get. Actually you might be better off asking a well established reseller/service provider. I bet someone at OWC would know. Or that big place in NY. They are more likely to have staff who have taken an interest in this kind of detail.

[Waragainstsleep]

You can find the service providers extended tests on isohunt if you want. Not sure which version you'd need though and some of them are big files. An Apple store might run one for free. No harm in asking them.

[tooki]

Yeah, there’s an Apple Store in Montreal. I’d take it there. They won’t charge for a diagnostic, but you will almost certainly have to leave it there.

[lland]

I have exactly the same issue with a 24in 3.06 Ghz iMac (early 2008).

The 'geniuses' diagnosed a HDD failure then they changed their mind to a logic board failure.

The iMac starts to the desktop (I copied from the HDD so that appears OK) and then hangs with a colour screen (not always grey) at a random time depending on what I try to do - it doesn't like it when I try to change any settings.

fsck - finds an error, fixes it but Mac still hangs - zapped pram reset smc still the same result.

Refuses to boot from disks but will show target HDD and boots OK.

Firewire target drive boot also causes it to hang...

If it is the logic board any idea what part needs to be repaired?

Could it be blown capacitors?

Could it be bad memory?

[P]

Could be all of those things. Bad logic board does seem likely though.