820-2101 Main power rail checks and troubleshooting poweron

I have a logic board in a personal computer. This is my first experience in this type of work. I get green light on the charger adapter, battery removed cause its dead, and both fans spin. No startup sound or lcd or keyboard lightup. The front button light comes on and power button turns fans on and off and fans will stay running which makes me think the machine is running but i don't have anyway to tell. Oh there's no video through external dvi connection either.

I went through and tested the main power rails. The G3H rails that I tested are PPBUS_G3H has 12.6V, PPDCIN_G3H has 16v not 18.5v which I think should still be ok. PP3V42_G3H has 3.4v.

Next I went to 5V rails. PP5V_S5 has 5v, then get stuck on PP5V_S3. All the points I'm checking at has 0v (C5850, L5850, U5850, C4740) I am definitely out of my league with understanding how this line is generated. I do have boardview and schematics. Unfortunately, this is my first time. So any pointers that could give me an idea on what to check next would be much appreciated. Hopefully this is the only problem and there isn't other stuff like nvidia chip issues.

Answered! View the answer I have this problem too

Is this a good question?

Score 0
Add a comment
Spread Fixmas Cheer
Get $12 off your purchase of $50 or more with code FIXMAS12
Spread Fixmas Cheer
Get $12 off your purchase of $50 or more with code FIXMAS12

1 Answer

Chosen Solution

]Let's reset the SMC. Remove the battery and mag-safe adapter. Press and hold the power button for 10 seconds. Hook both power sources back up and give it a try. Let us know your results.


First let's make sure of your exact machine. Go to the EveryMac link and input your serial number and let us know. http://www.everymac.com/ultimate-mac-loo...

The A1226 had the nVidia GeForce 8600M GT GPU. There was a class action law suit on this processor and subsequent Apple, HP, Dell and a couple of more repair programs that have long since expired. I have a stack of these machines all with the same problem and the last I check were uneconomically feasible to repair. A history on this machine would help immensely.

UPDATE for @gigabit87898 Gigabit on how to write an email

Here's what my current junk folder looks like after it has been cleared of the actual junk. I think you will see why I would have trashed your message

Block Image

Now I don't know why it is not displaying the image.

All it showed was Johnathan and email test

Was this answer helpful?

Score 4


I did as you recommended. I still get green light on magsafe adapter, at first fans come on for 3-4 seconds, then turn off. I pressed power button. Fans come on for 24 seconds then turn off. Nothing is displayed on screen and keyboard backlight is not lite nor is power button. Not sure what its called but the white light on the lock release button on the front does light up when fans spin.


This is what i got when i input the serial number. I know the history of the machine. It's a company laptop that has been in my possession since first purchased by my company. They pretty much excessed them. No repair has been done on it and the nvidia chip was not replaced by any of the repair programs. Is there anyway to confirm its the nvidia GPU and not something else. I agree that it is uneconomical to repair if the nvidia chip needs reballing or replacement. Would just like to know for sure before i trashcan this.

Apple MacBook Pro "Core 2 Duo" 2.2 15" (SR) Specs

Identifiers: Mid/Late 2007, 2.4/2.2GHz* - MA895LL - MacBookPro3,1 - A1226 - 2136


@spitfu Unfortunately Apple would never release the testing software that identified the problem, even after the recall program was over. That's why I have a stack of them gathering dust.


@mayer how much would you sell a few of those for?


Gigabit878 make me an offer i can't refuse. You do realize I can't test them at all. I'll weight about three and see if i can figures out how much shipping would be. I shoveled these before getting my hot air rework station so all they may need is a reflow.


Show 21 more comments

Add a comment

Add your answer

Michael Spivack will be eternally grateful.
View Statistics:

Past 24 Hours: 0

Past 7 Days: 4

Past 30 Days: 33

All Time: 480