Macbook Pro falls asleep, GPU issue, to bake motherboard or no?

Kris asked me on youtube about baking a motherboard to make it work again. I get this question a lot, so I decided to share with the rest of the class.

I was wondering if you could offer me some words of advice.

I own a - somewhat old by now - macbook pro 2007. I installed mavericks on it, which seems to be working fine. Seems. There is one issue when the computer falls asleep. It tends not to wake up. In the sense that its doing ok, but the screen does not wake up and the sleep-light keeps blinking. Nothing you can do to wake it up anymore.

No shaking, throwing, resetting whatever memory, reconnecting whichever whatever... the only thing that DOES work is the... yes... logic board bake trick.

And this is where I am confused. And this is what I would like to ask you about.

Maybe taking out the logic board and putting it into the oven for 195 degrees 9 minutes, is a slight overkill... Maybe there is something silly going on here that I did not think about doing...

so...

question 1. what is it that actually happens during the 'bake' that makes the logic board suddenly wake up from its beauty sleep?

question 2. is there an alternative way of achieving the same goal?

I mean... there is only so many times I can do the bakes, I did this 3 times already and I fear that the logic board will just get damaged one of these days...

Anyway, any tip or information will help.

Thanks

Kris

Hi Kris,

Firstly, the newer Oses can put some additional load on the older machines. Silly graphical effects here and there on Mavericks. It's not a lot, but if you have a GPU temp sensor on there, you'll see between Leopard & newer Oses, the GPU runs a little hotter when you have the eye candy turned on.

Secondly, 99% of the time, in your case, it is the GPU issue. I am guessing your machine has an 820-2101 or 820-2249 motherboard. The G84-602-A2 is a piece of shit and is the GPU on most of those boards. The G84-603-A2 is a lot better. A lot of the times, you can just solder the old one back to the board, and you are fine, but that is not the case all the time.

When you bake the board, you are reheating cracked solder joints and causing them to come back into place. Since you are baking the entire board and not one chip, I can't tell you exactly which component for certain is responsible – but I can give you two theories as to why it keeps fucking up.

a) The chip is actually bad, and it is just coincidence that it works after baking.

b) Solder needs flux to flow freely. The flux burns away each time you heat it. If you keep heating it, it becomes caked shit, and doesn't flow freely.

Dropping something like Kester 951 under the chip and then try baking, or reflowing the chip. It will help the solder balls set into place properly

You might just be fucked at this point since you've baked it three times, even if you baked it at appropriate temperatures. The board can actually flex from heat related damage over time, which makes it more difficult for the solder balls to flow into place. Once the board is warped, you're kinda screwed, 90% of the time.

c) You are not heating at a high enough temperature. For lead free solder, 195c is near the top of the curve, but not the top of the curve, to properly get that fucker back on the board. You need more heat.
Again, I'm tossing a lot of guesses out there because I don't have this in front of me, and I have limited information, but hopefully this helps you get some direction & perspective.

Thank you for your question!