MacBook Pro 13" 2010 G3 Hot 5,3V

[gerikerschi]

Hi all!

My Macbook Pro 13 2010 does not start any more.
I measured the voltage on G3Hot and I get 5.3V instead of 3.4V.
The Battery Pins 4 and 5 also have the 5.5V.
The MacSafe lights green (without accu).
Can anyone help me to find the problem?
I am sure, I have a problem on smc circle.

BR
Gerald

 

[maflynn]

All I can recommend is to take it into apple, though it being a 2010 model, is out of warranty.

 

[gerikerschi]

I forgot to write, that the board has a little liquid damage around the Lt3470!
I cleaned all parts, but no function anymore!
I read a lot of forum entries, but I can't find such a problem with a too high G3Hot voltage!

 

[gerikerschi]

Are there any data sheet with the voltages around the Lt3470?
I am not sure, if the Lt3470 is damaged!

 

[cookiesnfooty]

Are there any data sheet with the voltages around the Lt3470?
I am not sure, if the Lt3470 is damaged!

What did you clean it with? I spilt juice on mine and it was dead, however spraying with isopropyl alcohol spray and scrubbing it with a tooth brush brought it back to life.

 

[gerikerschi]

I clean it with sinkers cleaner, sopropyl alcohol and a glass fiber pin.
Then I have soldered down 2 ic's with hot air, cleaned and soldered up again.
Now are the short circles away!

BR
Gerald

 

[gerikerschi]

So, I measured the current on the LT3470 chip on my defect Logicboard (MBP 13 2010) and on a good Logicboard (MBP 13 2009)

current on both boards
Pin--Type------defect Logicboard----Current good Logicboard
Pin1 FB--------------2,1V---------------------1,2V
Pin2 BIAS----------5,42V---------------------3,4V
Pin3 BOOST--------11,2V---------------------6,8V
Pin4 SW------------5,42V---------------------3,4V
Pin5 GND--------------0V-----------------------0V
Pin6 Vin------------9,78V--------------------10,8V
Pin7 NC
Pin8 SHDN---------9,78V--------------------10,8V

Is the DC-DC converter defect?

 

[gerikerschi]

I measured C6994 with 220nF, R6996 with 200k, R6995 with 348k and C6995 with 22pF.
All values are correct!
I have one problem.
The resistor R6995 has 348k in desoldered state.
In soldered state I got 200k. Is there any parallel resistor or Kerko which one could be defect?

 

[gerikerschi]

Now I change C6994, C6995, R6996, C6990 and U6990 and I get the same current on G3Hot!?
What can I do/check at next?