Macbook turns itself off, not your normal hardware issue.

[Glorious]

So I have this macbook from a few years ago. I got it because the harddrive died and it was more or less gifted to me. I put a new harddrive in it, installed a fully patched 10.6 and it functioned fine for months. Several weeks ago, it started turning itself off within 2 or so minutes of inactivity. It would show the dialog that gives you shutdown options and then, within like 5 seconds, it would power down unless you quickly clicked cancel. This wasn't intermittent, it was so annoyingly regular that the laptop was rendered unusable. Fail to press a key or touch the pad for a moment or two, lights out.

So I tried everything I could think of. I checked every setting I knew of in Mac OS, checked every log I could think of, etc.. I'm by no means any sort of expert in Mac OS, but it wasn't anything obvious that a reasonable proficient user could discover. I then tried to use the laptop unplugged, plugged with no battery, no difference.

Here is the strange part.

I put it aside for a bit, but this weekend I fired it up with an ubuntu live CD. It worked flawlessly. Stayed up for hours, went idle, came back, etc.. Nothing was wrong. So, of course, I tried to re-install Mac OS 10.6. But it turns itself off when booting up from the installation disk unless I provide input activity. It did the same thing if I provide input until it runs the installer and then discontinue input.

I ended up installing Ubuntu on it, which again works perfectly fine, but this is awfully strange. I want Mac OS on it, not ubuntu. I've looked online, but I haven't found anything about this, so if anyone here as any ideas or knowledge, please lay it on me.

[SNM]

Possibly it's an issue with the keyboard?
I'm thinking something like a spilled drink is making a partial connection so the controller thinks the power button is getting hit. This may be something that Ubuntu won't notice (since it's not part of the standard keyboard), but if you tap the power button under OS X it'll pull up the shutdown prompt.

[Synchromesh]

I have some expertise with broken Macbooks and yours certainly sounds like a hardware issue. Keyboard might be the culprit here as previous poster said. You may need to obtain another for testing and try a swap. OS X is quite picky about hardware on many levels but blatant bugs in code like that are fairly rare so chances are it thinks something is happening that either does not or should not.

[Glorious]

Possibly it's an issue with the keyboard?
I'm thinking something like a spilled drink is making a partial connection so the controller thinks the power button is getting hit. This may be something that Ubuntu won't notice (since it's not part of the standard keyboard), but if you tap the power button under OS X it'll pull up the shutdown prompt

The thing is, it's not random. I haven't timed it, but it's got to be about roughly about a minute or two, and it's consistently exactly that amount of time. And, as I've said, it's directly tied to inactivity. Use the touchpad or press a key and it doesn't happen. Why would a partial connection exhibit such regularity? Also, I thought about the scenario you mentioned, so I deliberately hit the power button in Ubuntu. A shutdown dialog came up just fine.

Obviously I can't know that it isn't sort some of strange hardware issue, I just put that disclaimer in the title so people would look at this more closely because it defies all my assumptions.

I have some expertise with broken Macbooks and yours certainly sounds like a hardware issue. Keyboard might be the culprit here as previous poster said. You may need to obtain another for testing and try a swap. OS X is quite picky about hardware on many levels but blatant bugs in code like that are fairly rare so chances are it thinks something is happening that either does not or should not.

Yeah, again I was probably a little extreme. As I said, even the Mac OS DVD does this, so clearly something is wrong with my laptop. Clearly the upper case is the place to start, I was more wondering if anyone had ever seen something like this.

I'll revise my title.

[Synchromesh]

First and foremost! Tweak that PRAM! That resets board's power manager. Google it, it's quick and easy. Might solve your problem.

If that does nothing, try cleaning your laptop out. Could be that dirt or maybe a little oxidation is causing this. Take the top case off, disconnect all power and very carefully go around your board using q-tips dipped in isopropyl alcohol and compressed air. On more than one occasion that method produced surprising positive results. It won't cost you much.

[SNM]

Googling "OS X shutdown on inactivity" reveals a few threads, at least one of which indicates that replacing the keyboard solves it.
Other alternatives: installed any new software recently? I don't think there's a built-in way to set shutdown (instead of sleep) on idle, but something like Secrets may have a setting for that.
Edit: oh right, forgot the install CD also did it. N/m about software, then.

[kyboshed]

I'd try running it for a bit without any battery connected, if only to rule out problems in that area.

Also try 'Restore Defaults' in the Energy Saver preference pane (though it turning off during an OS install pretty much rules out software config IMO).

[FuturePastNow]

It's almost like there is a faulty temperature sensor telling OSX that the machine is overheating.

[WaltC]

I'm thinking there's something that 10.6 doesn't like about the MacBook you're trying to install into. You said it was a few years old--can you be more specific? Now reading that you ran 10.6 for months--yea, I'll side with the folks telling you it's a hardware problem. Something's gone bad that's enough to shut the 10.6 installer down, but isn't problem enough to bother Ubuntu... Ubuntu installation is far less delicate.

[Glorious]

I'm thinking there's something that 10.6 doesn't like about the MacBook you're trying to install into. You said it was a few years old--can you be more specific? Now reading that you ran 10.6 for months--yea, I'll side with the folks telling you it's a hardware problem. Something's gone bad that's enough to shut the 10.6 installer down, but isn't problem enough to bother Ubuntu... Ubuntu installation is far less delicate.

Yeah, as I said, it's almost certainly the upper case. It just defied my expectations that Ubuntu installed and worked fine.

The reason my original title was so insistent that it was NOT a hardware issue was simply so people would closely read my description, because this isn't an obvious or simple situation, and I tried all the usual troubleshooting.

Even with that, I get suggestions like these:

I'd try running it for a bit without any battery connected, if only to rule out problems in that area.

I appreciate the interest and the suggestion, but I clearly said in the first post that I did that.



So, thanks to SNM and Synchromesh for being so polite and when pointing out that my insistence that it wasn't a hardware issue was presumptuous. My usual heavy-handedness here certainly doesn't entitle me to such tactful treatment.

[kyboshed]

Even with that, I get suggestions like these:

I'd try running it for a bit without any battery connected, if only to rule out problems in that area.

I appreciate the interest and the suggestion, but I clearly said in the first post that I did that.

Yes... clearly a reading fail on my part.

Do the console logs reveal anything interesting? (/Applications/Utilities/Console)
Have you tried using an external keyboard? (Though I don't think using one disables the onboard keyboard)

[sampo]

Wow. I have this EXACT problem. My Macbook (white), throws up the "Do you want to restart your computer?" dialog every 75-85 seconds when the machine is INACTIVE. If I'm surfing the web, typing, etc., no problem. But as soon as I stop using keyboard and mouse, I get the dialog (after 75 seconds).

It's too regular to be a hardware problem, and the fact that it works fine when typing/mousing suggests it's not hardware.

I did the following:

- reset power manager
- reset PRAM
- reset power save settings
- opened up the case and cleaned it out to be sure it wasn't a short (even though as I said it's too regular to be a short)

I noticed that this thread has no resolution. Has anyone else seen this? I guess I'll have to take it to the geniuses at the Apple Store...

Thanks,
Dave

[Glorious]

I am the OP, and replacing the keyboard (i.e. the upper case) was the solution for me.

I don't know what model macbook you have, but I can look up what part I used.

[Synchromesh]

Just so you know, those older non-unibody Macbooks had a known defect of keyboard edges chipping away. If you have that issue Apple will replace the keyboard for free as part of a recall. I suggest you check it out.

[pikaporeon]

Just so you know, those older non-unibody Macbooks had a known defect of keyboard edges chipping away. If you have that issue Apple will replace the keyboard for free as part of a recall. I suggest you check it out.

Thanks for the heads up, the edges of my pad is chipping off slowly.

[sampo]

Thanks! I just replaced mine with a black keyboard (all I could find as none of the employees here use Macbooks anymore, all have Pros) and it seems to work! THANKS!

[Glorious]

Glad we could help, and it must have been nice to just have the parts lying around!