820-3115 3 beeps

[gadgetfix]

this is intermittent
i have run asd and on several occasions it passed
everynow and then doesnt turn on and has 3 beeps.

history is that it had very small corrosion on the side of u1800 rest of board is very clean

 

[dukefawks]

Usually a bad RAM slot, the one closest to the keyboard is the one that mostly causes it. Max out the other slot.

 

[gadgetfix]

Yeah. interesting thing is i tried the slots. one in top then one in bottom np. it usually occurs when i do both slots. i will test the slot again. is there any fix for this.

 

[aprendiz]

Sometimes i´ve found 2 or 3 pins not soldered on J3100, check pins 2-6-10-14.....

 

[gadgetfix]

Sometimes i´ve found 2 or 3 pins not soldered on J3100, check pins 2-6-10-14.....

aprendiz exactly as you said. i noticed recently the macbook when ever you tap it whilst it has a ram in the bottom slot would freeze. after inspecting under microscope i can see there are some cold solder joints. I touched them up and testing now.

thanks

 

[dukefawks]

It usually rips up the traces and "touching" up the solder will just make it work for a bit. I do not recommend to try and fix the BGA bottom slot, you are asking for trouble.

 

[gadgetfix]

dang. hope not.

 

[gadgetfix]

this one is working great now. customer was mainly concerned for data anways.