Updated Apple's "geniuses" spent two weeks and an estimated $10,000 in warranty costs fixing a MacBook Pro screen fault that was resolved with a single button press or three.

That's the word from photographer Greg Benz who has outlined the whole sorry tale on his website this week.

An initially frustrated and infuriated Benz reported: "My laptop 'failed' again for the fourth time today. The first two motherboard replacements seemed odd, but I was given a completely new laptop from Apple on the third failure."

Two entire motherboard replacements? What on Earth was the problem? Well, Benz reports, "the screen was pure black after clicking the power button and there was a slight fan sound. The only other indication that anything was alive was that the machine would still make an audible chime when plugging in power and the caps lock key light could be toggled off and on."

In short, after pressing the power button to start the machine up, the MacBook Pro's screen appeared to be completely dead. And Apple's geniuses were equally as dumbfounded, going to the extreme length of pulling out the guts of the machine and replacing the electronics – to no avail.

The back-and-forth lasted weeks with Benz dropping off his machine and waiting for the fix, before being disappointed again. New logic boards, new cables, endless phone calls, diagnostics, the secret special super-geniuses from corporate wheeled out – nothing could get the damn thing to work.

Until… one perplexed Apple employee decided to take a really close look at the screen. Literally – he shone his phone's flashlight at the screen and got in real close… and found that he could just make out the login avatar on the laptop monitor, suggesting the screen was working and the computer had booted up and was outputting the right display.

So, want to know what the problem was? We'll let Greg pick it up: "What was the root issue?….. Ready for it?…. I’m not joking…. the screen brightness was turned all the way down (not merely dim, but off)."

That's right, our Greg uses an external monitor when at home but if he closed up his laptop while using it, it would eventually go to sleep. So he just turned the laptop's screen brightness down all the way so that the screen wouldn't distract him.

So, the issue...

But – and here's where you can cut the Apple techies a little bit of slack – if the computer crashed or was shutdown, the screen would remain completely black after the machine was restarted using the power button. And no amount of bashing on the screen brightness buttons had any effect.

Why? Because he was logged out. But he couldn't see that. Because the screen was black.

"If you completely black out the screen when you shutdown, both the Apple logo and login screen are completely black at startup (no back light at all, even if you tried to view in a dark room)," he notes, adding: "The brightness is only increased to a minimum value AFTER you log in."

And, as he notes, "this same completely black condition is allowed when running recovery mode, target disk mode, etc at boot. So none of the normal troubleshooting will turn on a monitor that was black last time you used the computer."

How about connecting it to an external monitor? Nope, no good either. They are disabled during boot and login. An external keyboard? Nope.

So how did they finally get it back and working? An Apple genius – his name was Kyle – did a blind login. He hit the first letter of Greg's login name, hit return, and then let Greg type in his password and hit return.

Then did that, and lo and behold, the screen brightness buttons started working again and the absolutely fine, working perfectly desktop sprang into view.

In short, if you turn off the laptop screen via the brightness controls, it will remain off when you next start it up, and can't be brightened until you login, giving the impression the machine is virtually dead on power-up.

It seems that Apple's geeks have a few defaults that they need to change, and perhaps a support article or two to write. And if you’re wondering, yes, Greg was under the Apple warranty so the whole thing ended up costing him zero dollars but did cost lots and lots of time and caused an inordinate amount of frustration. ®

Updated to add

After a storm of attention, Greg's been in touch to now claim a mystery third-party program was to blame for the blank screen, though he declined to name any of the possible culprits. Here's his note to us:

The black screen at boot-up is something specific to my computer (ie, some software conflict created by other software I have installed on my computer is preventing OS X from operating the way it normally would). This is not an issue with Macbook Pros running OS X as it comes from Apple. I would not expect others to run into this. If someone were to somehow install the same problematic 3rd party software as me and run into this issue, the workaround is straight-forward: just wait a few minutes after hitting the power button (to allow the computer to be ready for you to log in), then type the first letter of your user account, click <enter>, type your password and click <enter> again. While it is unfortunate how much time was spent trying to figure out what was happening, there is no quality issue with my computer. I truly love this computer. It’s very fast and is a critical tool in my photography business. I have been using Apple computers for years and am glad that I can say that this is a machine I would highly recommend.

When we pushed for more details, he went on to say:

What I know is that this issue has not been replicated so far on other computers. As a photographer, I have a handful of less commonly used applications that integrate with the display system, so that's the first place I'd look – but it could be a number of things.

O...K.