820-3115 short to ground but no on components?

[roy.ruan]

hi guys,
having a 820-3115 a1278 board, short on PPDCIN_G3H.
removed F6905. short is on the pin2 still.

I checked and PPDCIN_G3H go to few places, then I removed almost all the components connected to it,including R6990,Q7085,Q5490.
but still short to ground. it's "0" in diode mode.

Look around and see like broken trace on one of the usb port, seems like it's dropped with something plugged in,and the very top layer of PCB has a crack.
L4705 removed, and pin2 is still shorted to ground. removed U4600, still shorted to ground


so found two shorts now, PPDCIN_G3H and pp5v_s3_usb_b_ilim

I tried injecting power to PPDCIN_G3H, only 1. sth Voltage already got the Amp to almost 5A.

and nothing is really hot on board but the clam from the DC machine.


doubting on the PCB layers maybe short and damaged? anyway to fix case like this?

thanks

 

[dukefawks]

I've seen that before, short in the PCB. RIP....

 

[roy.ruan]

thanks anyway man

 

[larossmann]

Not RIP!! https://www.youtube.com/watch?v=81kmdfdLuag

 

[dukefawks]

It is not RIP if the short was just on PPDCIN, but 5V_S3 to the USB is also shorted. I had a board with the exact issue too, isolated the shorts and it turned on but was brain dead.

 

[roy.ruan]

yea i know that drill method too, but the thing is that, you don't even know where the short spot is , so no way to drill. the short is inside the PCB layers.
it looks perfectly fine physically, no like those with burnt black spots..