820-2879-b magsafe blinking green and orange light in turn

[Yoel Ren]

yep, the ppbus coil pulse too, the pp3v3_s5 coil pulse ranging from 5v to 200mv to 0 to 5 and the cycle continue
and no voltage on pp5v_s3 coil

smc bypass did nothing..

 

[2informaticos]

"pp3v3_s5 coil pulse ranging from 5v to 200mv"
5V at 3V3 coil???
Check on its DC side.

 

[Yoel Ren]

im sorry, I don't quite understand what check dc side mean ?

 

[2informaticos]

C7251, pin2/L7220

 

[Yoel Ren]

so.., l7220 pin 1 and 2 is pulsing ranging from 5v-0v too
so does pin 1 of c7251

 

[2informaticos]

Check R7269/70, all traces and other resistors around U7200.
You may need to change the chip too.