Engineering Manager | Trail Runner | Stockholm, Sweden

iMac screen freezes caused by faulty hardware

The title basically spoils the ending, but here’s how my dealings with Apple went regarding the freezing iMac.

To recap the issue: ever since 10.6.3 some Macs produce video freezes where the computer remains running but cannot be interacted with. Screen can black out, white out, show stripes or just an endless beachball. The only solution is to hard reset or – occasionally – use ssh to log into the machine and issue a reboot command. The kernel.log is usually flooded with a particularly disgusting GPU dump.

There is a fairly extensive discussion about this problem on the Apple Support Communities board which started in March 201024″ iMac Screen Freezes since 10.6.3 update – pls help!

People in the thread determined that something in the video drivers cause the freezes and that the relevant kernel extensions can be swapped to their 10.6.2 counterparts which stops the lockups. Of course one loses two years worth of video driver updates this way. Regardless, I’ve been doing this for every OS X update since then.

Feeling that I exhausted all available options one day in February I was just fed up enough to exasperatedly email Tim Cook. After all some people did get a reply…

To my huge surprise I did actually receive a response from an Executive Relations representative who forwarded the issue to a Senior Apple Care Specialist. Although the warranty on the iMac has long been expired, they agreed to deal with the case based on the assumption that it is a software problem. I was quite hopeful we could finally find out the cause of this issue together.

Over the phone I was instructed to set up a separate partition with a fresh install of OS X Lion to prove that none of my installed third party software are the culprit. For weeks I was trying to reproduce the freeze on that installation with little success almost losing belief that it would occur until finally it did freeze out on me, classic rainbow cursor style. Logs and system information were gathered and sent over in hope.

Only the reply I got a week later was a major letdown: the engineers allegedly determined that the root of the issue is malfunctioning hardware. I was told that since the warranty had expired they are unable to offer a replacement video card or any other free solution. What’s infuriating about this is that my iMac is an early 2008 model; 10.6.3 came out on 29 March 2010, meaning I was most likely out of the 1 year warranty when I even had the chance to find out about the problem. Along with several others I was sold a computer with allegedly faulty hardware, with said fault well hidden during the time covered by warranty. That, or everyone’s video cards just fried the day 10.6.3 came out…

I seem to recall that replacement programs have been started for much less. Also we are talking about a company with enough cash to buy my home country’s national debt. And I still get to use a computer with a broken video card.


Yesterday afternoon I visited the Apple Store in Shinsaibashi to present my dead battery. In short the Genius found the battery defective and issued a replacement. The whole caper took about twenty minutes, waiting included. As always I was stunned by the professional and enjoyable environment of the store and the quality of the support.

I made a few observations during my visit. For one, there was a guy walking around checking the customers waiting for their Genius Bar appointment. He wore a T-shirt captioned ‘I can make things happen.’ In contrast, the Geniuses’ shirts read ‘Relax. I’m on it.’ I found these a lot cooler than the usual ‘Hello. I’m XY. Can I help you?’ name tags.

When checking the battery the Genius used the following method. First he consulted the System Profiler and checked the battery status. Then he attached an iPod (!) to reboot into a little battery checker program which reported in huge red text that the battery was bad. All this was done with me able to watch as well, so I even caught the line where the battery self-reported its bad status.

What I find remarkable is that he could have used some third-party USB stick, but in the name of product unity the battery checker was put on an iPod. Because little things like this matter.

Boomer's insides

I just got back from the Apple Store with the ill-fated black MacBook. It’s working fine, good as new, after the repairs.

Originally I asked for the keyboard to have swapped, since apparently it was the only part malfunctioning. The Apple employee I talked to defined the issue as “tier 2 accidental damage“. (If you’re new to the story, I poured half a liter grapefruit juice over the keyboard.) I explicitly asked the repairs to be canceled if the damage exceeded that of the keyboard’s and the LogicBoard needed to be replaced as well. The main reason of this being the fact that a LogicBoard replacement costs almost as much as a brand new MacBook.

Well, they called me yesterday, saying the repairs were done and I can pick the MacBook up any time I wanted. I went to Osaka today to do so. The laptop I received honestly looked identical to the one on the day when I just unboxed it. They cleaned the whole thing. I didn’t even bother looking at the maintenance reports until I got home…

And boy, was I in for a shock! They didn’t just replace the keyboard. According to the repair staff, they swapped – besides the whole top case with the keyboard – all the cables inside, including the HDD connector (which was corroded I admit, but it worked fine nevertheless), the cooling fan and the AirPort wireless card (which was also functioning, I downloaded updates with it before I sent the MacBook to be repaired).

And that’s not all of it. The report then continues to explain that during the standard testing the built-in camera was malfunctioning as well, so they replaced the LogicBoard too. And they did not charge me for it, for a reason still unknown to me. The MacBook is way out of warranty now and the damage was entirely caused by my clumsiness after all.

Thinking about it, the black MacBook now only has the DVD drive and the bottom casing with the monitor that are original. Everything else had been replaced.

I am now officially in love with Apple support. First they swapped the failing battery for free, and now I got a full LogicBoard replacement gratis.