The case of the missing battery.

So yes, there it sits, my beloved MacBook Pro, Retina, ca 2012, 0% battery, just completed an emergency graceful shutdown (on account of the 0% battery left, it seems - didn't it know that the power connector was approaching at speed?) Anyway, the MagSafe 2 was in my hand, approaching the docking port for the power it so desperately needed, mere inches, and it still decides it can't hang on for those few milliseconds. Ungrateful tyrant, is what it is.

I had been deep into an Android ROM build and maker session, when a helpful system pop-up warns me battery level is critical and I should do something soon or the system will execute a graceful shutdown. Now, in the state I was working at, there is no graceful shutdown - I had sessions open to work-threads running in the Google Cloud and, if my end dropped, they would, well, be running around headless, and in short order terminate. Which by itself is not unrecoverable, but the terminal session scroll buffers where they were helpfully displaying encountered build errors would be lost. I'd have to unwind some of the work to get back to a starting point where I can resume. So, no, let's abort the graceful shutdown by getting power to the demanding little tyrant. In this case, an Apple MagSafe 2 in my backpack, other side of the desk. I jump to get it, plug it into the power strip, and route the cord to the magnetic catch (- brilliant piece of design there, I love magnets, although - but that's another Lab Note.) And the moment I click in, the screen blinks off. Not so beloved right then.

Sooo, alright. No panic, right. I have been here many times - just breathe a few seconds, and press the power button, and bwongg - the happy sound of a Mac starting will emanate from the elegant microscopic speaker grill holes punched through the aluminum unibody design either side of the keyboard. I do love this MacBook.

Alas, what I get this time is an anemic whisper of one of the fans spinning up for a second, then sighing into silence. Then starting again, then silence. Ack!

Not good. Never heard that before.

The handy lights in the MagSafe 2 connector do the right thing - off for 1 second, green for a second or less, then orange. Perfect - the system is happy there is power from a power supply it recognizes, and then, happy it is charging the battery. So why will it not actually power on? I have grave visions of worst case scenarios flitting through my mind - the battery I replaced inside this beloved MacBook Pro earlier this year was a dud. I messed up some connector or connection putting it all back together. The surge of plugging in the power at the exact time the system was shutting down fried some power management controller. It's just an old (but beloved!) MacBook and I need to get a new one, now. (Hmm, that last one is not such a grave scenario at all, just expensive, but it would be funnn)

Assorted diagnostic steps where as follows -

• unplug and try the power button. Nothing.
• plug in and try the power button - whisper fans then nothing.
• hold power button down for 5 then 10 seconds - whisper fans then nothing.
• hold power button down while connecting power - AHA! Fans on FULL BLAST, bwongg... an apple icon shows up.

Sweet - my beloved MacBook Pro is alive! It's a little upset that things hadn't quite got shutdown in an orderly fashion, and there were a few startup complaints from Chrome and Skype and Zoom and Word and Evernote, but these were easily tamed and I had my system back.

Now, why are the fans blowing full speed, though?

Clearly it's not system load, as there is none, yet. And even had it been system load, I've never heard them go at it like this, and I've loaded this system some, in the past. A quick Google search shows up that maybe it's just temporary, and a reboot would take care of it. Nope. After shutdown, to start I have to do the same press power button while connecting power to wake up the system. And when the OS is up, fans are still straining for lift-off! More Google searching - perhaps putting the system to sleep, then wake will resolve the matter. Sure, quick experiment, let's try that. Alas, it sort of crashes into sleep, and won't wake except for the power hold and connect drill. And then, it's back to hurricane force fans and a full boot, not a wake from sleep.

So, go spelunking in system settings and power states and battery reports. First, the battery indicator in the status bar is absent. That's odd. What is the orange charging light indicator indicating if there is no battery? I force the battery indicator on in the power system settings, and the icon in the status bar blinks, showing no percentage and an x-out state, but it goes away, and the setting in the panel reverts to unchecked. I can't get it to stay on. I can blink it off/on/off with a single click, which is novel but not progress. In the system report, I have a memory of seeing a battery condition report under the power category, which is one of those things that is now so ingrained, I hardly know I know that, nor could I cogently tell people where it is, I just know it is there, somewhere, and when I am at my Mac, I can go there unerringly, but gosh, don't ask me to describe what to do to get there unless I am doing it. But now, there is only an AC Power information block. No battery mentioned. Not there. And, seeing as I operate from instinct here, I go looking to see if perhaps it was somewhere else. After all, perhaps I just thought I remembered it was there. But nowhere does it show anything about a battery. Try as I might, the OS is adamant there is no battery present.

Well, at least it is consistent - if there is no battery, then it would make sense that I can't turn on the battery percentage setting or the charge indicator on the status bar. For the battery that isn't there. Smart, bright people at Apple.

Except, of course, I *know* there is a battery, all be it at 0%. It's been at 0% before, and while it occasionally takes a few minutes to get the battery charged enough to let the system power on, it's never been this dead. Certainly, in the past, if the OS was up, it was willing to concede there was a battery, even if sorely depleted. Brand new territory here. Now what?

Google is my friend. And my friends at Google suggested -

• make sure the connector is clean and has no debris inside, or metal flakes - clear.
• cable is intact and no damage - worn, but functional.
• try another adapter (made no sense as the adapter was actually running the MacBook fine)
• make sure it was a 65 or 85 watt adapter - yup, it runs the MacBook fine, already, remember!
• bad battery, bad connector on battery, or bad SMC - all possible, but between OK upto running out of juice, and now, one of those happens?
• reset the SMC - System Management Controller - AHA, lets try that.

The trick to resetting the SMC is to hold the <shift> <control> and <option> keys down at the same time as the power key. While powering on the computer. So a 3 finger salute, a button press and a plug in, yes, let me just mutate another hand to accomplish that. It turns out a part of that instruction was inaccurate - the power being applied was irrelevant. Any time after power on, you can do those 4 keys and it resets the SMC. In fact, it resets the whole machine. I could see the SMC reset happening - the indicator lights on the MagSafe 2 blink and cycle, the fans stop anemically trying to spin up, and if already up into the OS starting up or running, it unceremoniously dumps you back to boot time. So I *know* my SMC is reset. Many times, and one more time for luck.

But, MacOS is adamant - no battery!

Back to dire visages of fried SMC's needing to be replaced, new batteries procured and reglued. A helpful friend I found through Google even had a video showing how easy it is to replace a SMC of the logic board - no kidding, here is the link. It's a bit like showing a video of Tiger Woods hitting a hole in one, and going - see, it's easy, you just hit this ball, and boom, in the hole it goes. I mean, the SMC is a BGA surface mount package in a sea of tightly packed surface mount components. It would take me years of working and reworking circuitry to get to the level of daring exhibited in that video.

One clue in the video is that the light on the connector is dead if the SMC is dead. Mine are functioning as before, so perhaps, not my SMC. Still dark and dire thoughts about bad connectors and dud batteries.

The other helpful (imagine the air quotes there) folk were talking about updating the OS, that I have liquid damage, and I don't really want the battery icon in the status bar, anyhow. But perhaps resetting the PRAM would do the trick - this is another reset option to have the Mac forget things it normally remembers even if there is no power - like the time of day, how loud the speakers were, display settings and other little things you like to keep the same from boot to boot. This is a 4 finger salute - Command, Option, P, and R just after the first signs of life, and it will clear and cycle back, so the bwongg will sound twice.

Ok, done that. No luck, still no battery.

Now, the mac has been running with fans in full power take-off mode for an hour or two, so the battery that is in there, if it was getting any charge, would have been nudged away from the needle pegged at 0% by now. But, still no luck with no signs of life if the cord is not connected. I had also noticed uncharacteristically unstable behaviour - if I had my Display Port monitor connected when I log in, it would crash the system. But not if I connect it after I log in. And also, not if I use a non-admin account. So even the thought that I could learn to live with 35 extra decibels in my space notwithstanding, there was still something amiss with my trusty macbook.

There were also a few instances mentioned where randomly connecting another power supply made magic happen. Alright, try that last ditch diagnostic. My partner has the other MacBook Pro, the smaller version, which she loves. And her power brick was in her backpack, also other side of the desk, just three steps further than where mine was, so as time was of essence, naturally I went for the nearest, quickest route last time. Now, taking a leisurely walk around the desk wrapping up the cord on my brick to substitute with hers - we have a pact that the power supplies are always in our backpacks unless actually powering one of our laptops - I see that I had the 65W MagSafe 2 brick, and she had the 85W one - huh, that must have been swapped inadvertently as fit and form they are identical.

So I get the 85W MagSafe2 to my desk, and snap in the connector, and bwongg! Sweet sound of success. Fans were idling, happy apple logo was glowing, OS was booting, battery icon was showing, and all was well in the world.

A very long tail, indeed. A very, very happy ending. And one more thing I now have ingrained - use the provided power adapter - even if an equivalent marginally lower rated one almost always works, I have discovered here that in the extreme case of 0% in the battery, and the surge of powering on the whole shebang is just fractionally too much for the 65W MagSafe 2, but within range for the 85W MagSafe 2. So, check it first.

And finally, while I might moan that the folk at Apple charge a lot for their product, and perhaps are not the most sharing about how to independently repair their product, or (apparently randomly) drop support for perfectly fine examples of their earlier work (like the other three MacBook Pros, ca 2008 now relegated to never being able to see past El Captain and 10.11.6, but still going beautifully strong!) they would ship a MagSafe 2 65W if that were adequate for the MBP Retina 15. And if they didn't, and provide a 85W nearly identical power brick, it's for sound engineering reasons.