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Apple released the MacBook Pro 15" Unibody with a new aluminum upper case machined from a single aluminum block.

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MBP Unibody won't power on

Hi all.

My old 15" MacBook Pro Unibody (2.4 GHz late 2008 A1286) won’t power on.

I’vet tried the various reset PRAM / SMC options, removing battery etc.

I know the charger is working. The machine won’t run when it’s connected to charger with the battery removed. So I’m pretty sure it’s a hardware issue.

I have a second machine to use for spares - which I can use parts from to repair the first machine.

So my question is where to begin. Replace DC in board? Logicboard ? Other parts? Any advice on diagnostics, most likely source of problem and best order to replace parts by trial and error would be v welcome.

Many thanks

Dan.


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You state the MagSafe charger is working but you didn’t tell us what the color of the LED is it Amber or Green when you plug it in. Is the cord and the connector in good shape? Check out this Apple T/N Apple Portables: Troubleshooting MagSafe adapters Make sure you have the correct charger and the connections are good. If it’s not lighting then your DC-In board likely needs replacing (inspect it first).

You should also check the onboard battery checker which will tell you the batteries charge & health. How many of the LED are lit? Are then blinking or steadily lit?

Lets start there before we go forward with anything deeper.

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It's the correct 85w Magsafe charger and it powers and charges other machines. When I plug it in with battery installed it turns orange, then eventually green. At the moment it's orange - and when I press the battery test button I get 3 green single flashes. I guess this suggests the battery is almost discharged and it may well be in poor condition.

If I remove the battery the MagSafe light is green. The battery test button produces rapid green flashing lights up and down the battery test lights (indicating no battery installed ?). But the machine still won't start. My understanding is machine should run off the MagSafe without the battery installed. So does this suggest failed DC In board or logic board ?

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The blinking LED's with the battery installed is telling you your cycle count is over 1000. Basically, you need a new battery!

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Hi Dan - thanks for your advice, just to be absolutely certain it is the battery, a bit more detail...

The laptop had been in a cupboard for 2 months so battery would have been discharged. I then attached MagSafe (which turned orange) and pressed battery test button - that's when it flashed green three times. But after a couple of hours on charge, the MagSafe light turned green, and when I pressed the test button all green LEDs light up. Doesn't that indicate the battery is fully charged and should now start the machine?

Is Mac@tellarspace definitely wrong when he says this machine should power up from the MagSafe with the battery removed ?

Thanks again

Dan

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OK so the battery wasn't fully charged then when you tested it.

If the battery is fully charged MagSafe is green and all of the battery test LED are lit and stay lit then your battery is OK then!

At this point lets do a SMC reset How to reset the System Management Controller (SMC) on your Mac

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Thanks Dan. Have just tried SMC reset as advised - removing battery and holding down power button for 5+ seconds - still nothing. Dead as dodo. The Apple SMC instructions don't say whether MagSafe should be connected or not while doing this - tried it both ways, nothing.

And yes, can confirm MagSafe is now showing green, all battery test LEDs light up green when button pressed. So suggests battery is ok...

So what's that leave? Sounds like DC board must be fine? Logicboard.... ?

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The Mac should turn on with the battery removed and charger plugged in. It could be the charger or the wall outlet.

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You're thinking MacBook Air or retina systems, not this series.

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@danj No, I'm not. You can open it, remove the battery, and connect the power adapter. It should boot.

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Not the older Unibodies, the newer Retina will! As well as the MacBook Air's will boot from MagSafe alone.

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Not sure what the first reply was, the moderator or Apple Support anyone..anyone? Was the 800’# listed? If you can get the system to boot long enough for PRAM lol then you don’t have a battery issue. “Lets”? Did he need to open a ticket with you :) Jk. great place to start, lead to #2. but I am a bit confused, how can he attempt PRAM and SMB if the machine won’t even power on.

I think we are leaving out the obvious. In a car, you have an alternator, a battery, and then the most important most forgotten part of most older cars, the COIL THE CAPACITORS that supply steady AMPED UP power to the mainboard. I have seen some pretty easy OR BAD MESSY issues with power on other models of that generation, especially the MacBook whites, which I have to imagine use very similar systems. (I don’t have the teardown in front of me) depending on the power supply, some have 2 capacitors on the power system that I know can both are standard parts and can be ordered at any electrical supply and soldered on if they haven not already cooked as the battery discharged completely into the system.

Im not 100% sure if this is applicable to your specific mainboard(still trying to find the system or revision teardown), but if you are handy with your toolkit, soldering iron and have a steady hand, if the power system capacitors went visually they will probably have gone from round to bulging, and often even without opening the device if they have gone, you often can smell the unhappy smell of burnt electrical components. Apple has varied power supply systems, but I have to assume that the 2007-2012 non retina, removable batteries were not all that different from model to model.

Second response Agree totally BUT if you have the technical prowess check for the smell of electronics and bulging capacitors which can be replaced. HOWEVER, there is/was a known issue with the power supply, and if you can rule out hardware that’s what I would do before a battery, because you are right if its a paperweight, there is no need to spend more on replacement parts for a 10 year old Mac, when you can spend the same money on a loaded 2015.

https://discussions.apple.com/thread/125... , https://discussions.apple.com/thread/134... etc. there seems to be a lot of similar problems. OS itself as we know can damage certain percentages of machines hardware indefinitely, El Capitan and Lion were notorious for kernel panics and cooked hardware, if you fall under this, it may have been some kind of systemic failure of your power supply as they are much smarter than usually thought.

But again, unless your soul is on that computer (just pull the drive), don’t waste the money on a 2008 15 inch replacing the battery before you rule out hardware failure. and if you aren’t good at hardware take it to a repair shop that still does repairs rather than swap-outs, before spending 200 bills, check the capacitors (which I don’t why apple never self contained them in the battery in the first place, the system will get NO power regardless of battery.

BTW 1000 Cycles is impressive.

Here are some links that I have used for similar issues: https://www.youtube.com/watch?v=zu1n-bI2...

to fix your power supply if its frayed or worn, not all that easy.

Here are some about the capacitor problem and other possible Soloutions now that I have done a bit more research, it seems this is very VERY common.

http://forum.notebookreview.com/threads/... (thread with more information.

https://www.youtube.com/watch?v=qY5oba8T... (Bad capacitor replacement)

Just duckduck, and shoot me a message if you need any tips or repair people in your area.

B.

Just found this on the teardown MacBook Pro 15" Unibody Late 2008 and Early 2009 DC-In Board Replacement

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