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Help with personal 820.4924 board

7

7zarkie7

New member
Hi,

I am trying to fix a 820.4924 board for no other reason than to learn something new and save a macbook from the bin - i have never done anything like this in my life so it has been quite a curve !

The symptoms are that the mag safe orange light never goes green and the screen was showing a low battery picture but would never progress no matter how long left on charge.

So i removed the board from the machine - i only have a macbook air magsense 2 charger in the house which i understand should work to power up the board.

The board shows no signs of any damage so i followed the videos online and used boardview and the schematics to find that

1. PP3V3_S5_SMC = 3.42
2. SMC_BC_ACOK = 0.V

Which i think narrows the problem down to R5187 - again looks with no visible signs of damage

Am I correct in my thinking ? is there anything else i should be doing as regards tests here ?

Mark
 
Last edited:
2informaticos

2informaticos

Administrator
Staff member
Magsafe light will switch from orange to green ONLY when battery is fully charged 100%.
It stays orange even if no battery connected, as normal behaviour.

"SMC_BC_ACOK = 0.V"
You should not even get light on Magsafe.

Post exact voltage for PPBUS_G3H.
Also check diode mode to ground for SCL/SDA lines of battery bus; no battery, nor charger connected.
Less than 1% differenece allowed.
If not, post voltage for these lines too.
 
J

JohnB8812

New member
A 45 watt charger will NOT work on this board whatsoever you need a 60/85 Watt OEM MagSafe 2 before we can continue. When you get one, see if the machine powers on without the battery attached
 
2informaticos

2informaticos

Administrator
Staff member
45W charger will not start the board alone, but should charge the battery.
When battery gets some charge, it should start pressing power button; both charger and battery connected.
 
7

7zarkie7

New member
Well - the 45W charger does not start the machine and as the battery was dead ( i didnt know this) it could not charge the battery. Therefore it looked like the board was faulty. As soon as i got the right charger the machine works but tells me that the battery is needing replaced. So for this board a 60w charger is needed before doing anything else. A lesson for me right there ! I have learned a lot though poking about so nothing lost :)
 
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