2012 a1286 820-3330 no video output

[roy.ruan]

hi guys
having a 820-3330 board. pretty clean and well kept condition,nothing spilled on it.

it can power up,all power rail present, you can hear the chime, but nothing on screen.
not the no back light issue, it's no image at all,same as external.

as for measurements, PPVCORE_S0_GXF = 0.8-0.9 ,CPU roughly 0.8 , PPVOUT_LCD=0V, BKL_EN=0V.

really have no idea now, tried to heat up (wram)the GPU with heat gun for about 30 secons, 200-250C. nothing change.

doubting on GPU, any ideas?

I searched a bit on forum,seems like someone else got this similar issues before but didn't get solved, any one came across this and solutions?

thanks in advanced.

 

[dukefawks]

SMC_LID? Tried external LCD with internal disconnected?

 

[roy.ruan]

smc_lid=3.3
yes, tried external but still no image

 

[dukefawks]

Could still be a bad GPU. I had one this week that did not react to heat, replaced GPU and worked.

 

[roy.ruan]

Im thinking the same thing. hate to call customer in this situation and add the price. cost of this chipset is around 60, should've charged more