Home Forums Mac Software Mac Operating Systems Very weird charging problem with Macbook Pro

I have an older, aluminum (non-unibody), Core 2 Duo 15" Macbook Pro that I got secondhand. When I got it, the battery was in bad shape, so I bought a new battery for it.

Lately, it has developed a very strange charging problem that I can't seem to get a handle on.

I partitioned the hard drive and installed OS X Snow Leopard on one partition and Mountain Lion on the other.

When I'm booted into Snow Leopard, everything is great. I can connect or disconnect the charger at will.

When I'm booted into Mountain Lion, it won't charge when I connect the charger. I attach the charger and...nothing. The little light on the charger doesn't even come on green, much less orange.

If I shut it down, or restart in Snowy, it works, and if I leave the charger connected and restart into Mountain Lion, it still keeps charging...but if I disconnect and reconnect the charger when booted in Mountain Lion, nada. Nothing. Zip.

Happens in any user account. Reinstall doesn't help. I have never seen a problem like this before. Any ideas?

Weird!

Have you tried safe booting into Mounty?

The Core 2 Duo MacBook Pro doesn't meet the system requirements for Mountain Lion, according to Low End Mac, so maybe this problem reflects an incompatibility between Mountain Lion's power management and the earlier hardware (i.e. Mountain Lion doesn't know how to initiate the charging process)?

According to Mactracker and Apple, at least some Core 2 Duo MBPs, beginning with this one, can run Mountain Lion.

Not sure what the point of the Apple link is, since Cupertino in its infinite wisdom declines to identify Mac models by processor name. Low End Mac refers to the 2007 MacBook Pros as "Santa Rosa" models, I guess to distinguish them from the earlier Core 2 Duos, but you're correct that the 2007 models are in fact Core 2 Duos. The real issue is: which Core 2 Duo does tacit have?

Artie's right. The name 'Core 2 Duo 15" Macbook Pro' is insufficient to ID the actual model. There were 5 different 15" C2D MBP models starting with the 2006 MacBookPro2,2 (A1211), the final model being the 2009 MacBookPro5,3 (A1286). Only the first model is OS limited to Lion (10.7.4); all others should be able to run the latest OS to date.

If the problem model is the one Dave talked about, the charging issue may be as he suggested. If not, any of the various charging issues that were reported even before ML may be solved by standard approaches as listed here.

Alternatively, this charging anomaly may be related to the battery drain issue of early ML iterations, unless of course you're running the latest & greatest where that's supposed to be fixed.

Finally, I wonder (a) what OS/DU version you were running to partition the drive, and (b) if you see the same thing when booting into ML from another drive. Variations in anomalous behavior might give you a clue as to what's going on.

We can rule out the last two of those, though:

I included the Apple link because Mactracker is synced with Apple on ID terms other than processor names.

Both sources refer to the "Mid/Late 2007" MBP as the earliest one that's Mounty compatible, and MT tells that it is not a unibody Mac.

Aside: According to the Apple doc to which I linked, tacit could not even have installed Mounty on an earlier C2D than the one I referenced.

I should have been more specific. I have a MacBook Pro 3,1, which is the earliest MacBook Prro that is officially Mountain Lion compatible.

Firmware update?????

I seem to recall one of those awhile back that was in response to charging issues eerily similar to those you describe......is your charger a 90° angle head (new style) or a "T" head (old style)?

It's a new style head, though the computer shipped with an old style head; it was replaced by Apple under the warranty replacement program for power adapters that tended to fray.

Software Update shows no firmware update.

Interestingly, the problem has resolved itself just as mysteriously as it started. I'm booted in 10.8 now and it's charging fine. It went through a period of abouta week when it wouldn't charge in Mounty, and now it's back to working A-OK again. I'm utterly flummoxed.

the L headed magsafes required a firmware update to work at all with a number of the older "model T" (hah.. model T... nice) magesafes. We ran into this when apple started selling only the L and customers were buying replacement L's when they cat chewed their cord etc and they weren't working.

This is a firmware issue though, with the SMC iirc. If it works in one OS it should really work in the other.

Also, when it didn't work, it didn't work. No charge, AND no power. Your description I think said the only problem was with power. OS issue? If available, boot a same model same os in target mode and boot your machine up off its hdd to confirm a software issue.

The fact that it works fine in one OS but not the other would seem to rule out a firmware issue to me.

The fact that it's mysteriously started working again is totally baffling. I'm actually wondering if it's not a problem with the power adapter, though why it should matter what OS is running is beyond me (coincidence, perhaps?).