820-00163 powers up no chime or display, question on power rail variations

[laptopcity]

Hi, ive got an 820-00163 powers up no chime or display ive checked every power rail and all are correct except some variations on pp1v35_gpu_reg which should be 1.35v and i have 1.48v, ppvddc1_so_isense should be 1.12v and i have 0.9v and ppvcore_gpu which should be 1v and i have 0.84v could this be enough of a difference to cause a problem ?? , i did have a look at pp1v35_gpu_reg and found that the voltage at L8710 should be 1.05v according to the schematic but i have 1.48v , could this mean that q8710 or u8700 could be at fault or is the schematic off on voltage and im just gonna get headache P.S this board has no signs of any damage anywhere

 

[aprendiz]

Do a PRAM reset....

 

[laptopcity]

Hi yes thats the first thing i done but no joy :-(

 

[dukefawks]

CPU Vcore present? Without any history on this board this one will suck. See if this thing is <2 years old, if you are in the EU Apple will fix it under warranty.