Short on pp_vcc_main that produces no heat
So Iv had this twice now in the last three days and its driving me insane. It goes as follows.... Customer drops in a 6s that's been water damaged. Won't charge, won't power on, changing Tigris, tristar, active diode makes no difference. 3v and 1.8v at tristar surge up to operating voltage, drop to zero then back to operating voltage again. Short is detected on pp_vvc_main.
Iv tried plugging in a power supply and giving it 4 volts 2.2 amps and no heat, not a %#*@ thing. I even tried putting the board in isopropanol and then putting it in front of a fan and then using my flir camera to look for heat, the isopropanol and fan make the board really cold so even the lowest resolution camera can see a heated area on the board, but nothing, even after leaving it 5 mins.
Once I'd given it up as totally dead I put 8 volts into it too see if anything would heat up then,it was dissipating 4.4amps but all that was happening was the power supply leads were heating up, the board was still totally cold.
So I'm totally confused now, how is it possible for a board to sink that much current and not get hot in the slightest ?.
Has anyone ends had this problem with a 6s ?, as Iv had the same problem with same symtoms to the letter in 3 days.
The thing is Iv had shorted caps and ic's before and they generally get very hot when you ram 4.4amps through them, this on the other hand does nothing.