[SOLVED]820-3023 fan spin, S0 present, no boot

Joesipaq

New member
Hello all,
So I have a MBA 2011 A1369 (EMC 2469) that has no "deadly" signs of water damage. (fly piss on a cap - cap tested fine, cleaned well)

There is no chime or beeps, but most all S0 power lines come on. ALL_SYS_PWR_GOOD is high,fan spins, green light, then amber.

The only voltage i notice missing is PPVCORE_S0_AXG_R. There is no voltage on pin 13 U7400.

Where would you go next?
 
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Joesipaq

New member
R7402 @ 91.3k
Pin 1. CORRECTION 3.31V
Ping 2. 0.3v but after probing pin 1, jumps to 7.74v (only when fingers are resting on probes - so with high resistance from pin 1 to ground, pin 2 gets 7.74v for a few seconds.)
 
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dukefawks

Administrator
Vcore present on L7510? If yes then all you can try is another BIOS and possibly hidden corrosion somewhere. These board are however infamous for RAM issues which is not worth bothering with.
 

Joesipaq

New member
1.17v present on L7540.
That is a little low though is it not? I haven't messed around much with vcore so I'm not sure what its normal range is.

Thanks! Ill probably get another bios ready to try out too in the mean time
 

Joesipaq

New member
as an fyi, the corrosion that i didn't think was important was on cap C1696 and apparently C162E. the one right below and closer to the ram. But they are now reading 1.05V.
 

dukefawks

Administrator
Vcore is present so all power should be fine. Try another BIOS to be sure. After that it can be anything from crap under SMC to bad RAM/CPU/anything.
 

Joesipaq

New member
I changed out the bios, transfered over the me region or what ever its called, then on boot up, got that good ol 3 beep. So progress!

Looking a little better at the housing, it had some pretty decent drop damage a few times - so i thought i would reflow the ram to see if there was any luck.

Bumping each one, i messed something up and caused no boot at all. Decided, why not try reballing all the ram, see how bad it truly is.

1248 balls later, everything is back on and the system is working great! No asd errors - besides low capacity battery.

So, this one is solved! Thanks for the help. Happy fixing
 
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