magsafe adapter not lighting up

Get a new battery for it. See if you can source a replacement battery from www.lacomputercompany.com. It would be best to get an OEM battery (made by Apple) for it instead of an aftermarket one, but it's probably just the battery that's wacked out. There's a small % chance it could be something else, but the Service Battery indicator is enough to tell you the battery is shot to begin with.

If the power adapters worked properly on other Macs then your MBP should operate without a battery when attached to a power adapter (though not as fast). It sounds that you have other issues besides the battery. A trip to the Apple store genius bar or AASP is recommended for a diagnostic evaluation.

Ciao.

The unibody Macs aren't supposed to have user serviceable batteries (i.e. you cannot remove it without taking the bottom cover off). Because of this, the circuitry is built so that a battery is necessary to work with the charger plugged in. You may find this different, but some of the plugs on the unibody Macs on the batteries complete the circuit for even normal powerup with just AC adapter. Without a battery in it to complete the circuit, it won't power on.

SwankPeRFection, greetings; You said "Without a battery in it to complete the circuit, it won't power on." in regards to unibody MBPs. Is this applicable to all, or just some of them? Have you tested this yourself? I would be very interested in knowing the source of your information.

Ciao.

Sheila Anderson1 wrote:

Oh dear. So perhaps getting a new battery would help matters?

Possibly, but a trip to the store is indicated by it not running under wall power, with or without a battery

OGELTHORPE wrote:

SwankPeRFection, greetings; You said "Without a battery in it to complete the circuit, it won't power on." in regards to unibody MBPs. Is this applicable to all, or just some of them? Have you tested this yourself? I would be very interested in knowing the source of your information.

Ciao.

There's two different types of batteries for the unibody MacBooks from what I've seen. The older ones that came out in like 2009 (like the OP has) and the latest models like 2012 that have a different connector on the internal battery. From what I have see, some people have been able to get their computers to power up without the internal battery and some have not. They replace the battery and it's fine after that. I haven't been able to test this myself, but I have worked with other laptops that have internal batteries like MacBooks do and they behave like this. That battery is required to be in to complete the circuit and power up the board.

A MacBook that's dead all the way (logic board dead) usually behaves to the likes of not wanting to do anything or it powers up and beeps like 9 times. That's not what the OP is describing, so unless the logic board went bad enough to show a battery that needs servicing and also no longer charge any battery in it, then it's probably not that.

I agree that there are different type connectors on the unibody MBPs. I also know that a healthy MBP will operate with the power adapter and the battery disconnected (although the performance will be compromised somewhat). I speak from experience with my MBPs (all of them power up without the battery), and what has been reported by respected veterans of this forum.

What other manufactures do in designing their computers is not germane here. It is what Apple does. Note that when the MBP is fully charged (100%), the SMC will then disconnect the battery and only will start charging it when it drops to less than 95% of charge. Thus the battery does not have to be in the circuit for the MBP to operate.

I have not heard of a MBP that cannot operate on the power adapter and comes to life with the battery installed. That may be true for non Apple laptops. Based on the symptoms that the OP has provided, it is a fair conclusion that there are other issues besides the battery.

The syntax of you last paragraph leaves me to speculate as to your precise meaning, but I think that the important issues have been covered.

Ciao.

OGELTHORPE wrote:

I agree that there are different type connectors on the unibody MBPs. I also know that a healthy MBP will operate with the power adapter and the battery disconnected (although the performance will be compromised somewhat). I speak from experience with my MBPs (all of them power up without the battery), and what has been reported by respected veterans of this forum.

What other manufactures do in designing their computers is not germane here. It is what Apple does. Note that when the MBP is fully charged (100%), the SMC will then disconnect the battery and only will start charging it when it drops to less than 95% of charge. Thus the battery does not have to be in the circuit for the MBP to operate.

I have not heard of a MBP that cannot operate on the power adapter and comes to life with the battery installed. That may be true for non Apple laptops. Based on the symptoms that the OP has provided, it is a fair conclusion that there are other issues besides the battery.

The syntax of you last paragraph leaves me to speculate as to your precise meaning, but I think that the important issues have been covered.

Ciao.

No, the SMC "software" disconnecting the battery from charging isn't the same as removing the battery plug. It just stops the charging, but all the other pins used for monitoring are still in use to poll %/health/etc. So, no, it's not the same.

What the last paragraph meant is that the OP's laptop works and indicates a battery that needs servicing and won't charge. Last time I checked, that's more proof that a battery needs replacement than a logic board needing replacement. N'est Pas?

SwanklPeRFection, greetings: What is relevant is that fact that the SMC disconnects the battery as a power source. Monitoring circuitry is of no consequence in this situation.

Ciao.

I just recieved a replacement battery for my '08 MacBook Pro and when I installed it it's not charging. I took it out and reinstalled it a couple of times to reset and nothing. Any solutions?

An Apple battery? or a 3rd party?

3rd party.....same model number

Who knows, there is a reason the 3rd party batteries are cheap. try a real Apple battery.