820-00165a no EDP_BKLT_EN

TBFix

Member
Hi Im working on a Macbook air A1466 which was water damaged and was dead with no led on charger.
I currently have it powering up fan spin. All major voltage are present.
I have no chime or screen and am not sure of usb activity but usb mouse red led flickers at the start of power up.

Currently I have no EDP_BKLT_EN and no output from Q77706. U7701 has power on pins C4/D1/C1 but no output .
The unit draws about 350ma.
L7701 ha no voltage on it due to Q7706 not passing voltage pins 3 and 4 have 8v.

i have flashed the bios with a file from the forum but still the same.
Any help welcomed
 

2informaticos

Administrator
Staff member
USB mouse light should be steady, but can trick you.
Always better to use USB boot pendrive with Link LED; if flashes, then 100% USB activity confirmed.
No reason to search video, if no USB activity on board...

If water damage, first step should be reball SMC and check all SPI Bus Series Termination resistors and their traces.
Maybe need to heat CPU with good flux and UC the board too.
 

TBFix

Member
Yes I tried 2 screens 1 cracked and the backlight is the same on both, will try the return resistors.
Thank you for the assistance.

Edit.. LED_RETURN_2 using diode mode is reading .019 all the rest are .63 so I guess U7701 is bad.
 
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TBFix

Member
I seem to have sorted out the backlight issue but when testing the battery to see if it charges I now have another issues. The system doesnt see the battery or charge it.
With just the battery in I get 8.23v on ppbus_g3h F7140.
I have 8.23v on pins 1-3 on batt connector , pins 4 and 5 3.3v fluctuates frpm 3.3 - 3.0 on both pins. Pin 6 is at 0.22v.
R7151/52 read ok
I have tried 3 different batteries
 

TBFix

Member
No I have 1 charging and running off the same model board in a different chasis.
So this battery has some charge and will power up on the other chasis but wont on the one Im working on.
 

TBFix

Member
I have 8.23v on pins 1-3 on batt connector
3.3v on both SCL/SDA lines.

Os does not see a battery. Everything else works fine. I managed to install fresh Os. So there doesn't seem to be any other issues other than seeing the presence of the battery.
 
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2informaticos

Administrator
Staff member
I was asking about SCL/SDA voltage, apart of diode mode reading.
If both steady 3.3V, change SMC.
You can try changing ISL6259 first, just in case.
 

TBFix

Member
Hi as previously mentioned SCL/SDA voltages are 3.3v . Isl was changed for new one but still the same.

How to know if the board sees the battery?
 
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TBFix

Member
Reballed the Smc an seems to be working now, charges and runs from battery . Will test more. There must be an easier way to align these smc chips?.
 
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