Recent content by 2informaticos

Check diode mode to ground on missing voltage rails. Compare readings with good board.

12V on backlight output may be caused by bad UP800. But other adjacent components may impede it, or QP800-3 to boost up the voltage.

Where did you get the new BIOS file? Just in case... https://drive.google.com/file/d/1xXgXuUDgPLgQTYbM_3qnRzQuAbLZfM15/view?usp=sharing https://drive.google.com/file/d/1MjiFvpavU1hEerrDCWTgQBUsMfAzc8Tt/view?usp=sharing

That's bad; what about diode mode?

Check the behavior in safe mode. Also run embedded startup diagnostic.

R6040 is 0 ohm resistor; it MUST have 3.8V on both pins. It is burnt; if no short to ground on pin 2, replace it and test. R6043 is 2 Mohm resistor; can't be properly checked onboard. Your problem may be C/U6040; which can damage R6040.

Did you test with known good screen?

Not sure if DFU does an exhaustive check on the NANDs. The 20s cyling usually points to SSD problems. Some NAND may have bad locations.

Any history available? Did you check diode mode to ground on backlight output? J8500 gets 5V_S0SW_LCD?

Compare diode mode readings on big coils with good board. The drop on G3S voltages can be caused by a problem on Intel side power rails; S5 to S0.

You didn't say anything about 1V8 XA/B LDOs. What about PPBUS_G3H voltage and diode mode? Compare diode mode readings, between U3100/200, on all (4) LDO lines.

Many of the mentioned components connect with CPU; it may be damaged already. PMU_VDDHI is correct, so U8100 should deliver steady LDOs. Check them for voltage pulse and diode mode to ground. Also check U7700 LDOs. I suspect you have more corroded components, or traces; even under some BGA chips.

First of all, welcome to the forum! Is the CPU core steady 1.05V after 10-15s? PLT_RESET_L comes high? You should try known good BIOS. The data can be recovered with dedicated tool over Lifeboat connector (J9600), even if Intel side doesn't work.

U8100 generates more voltages from 3V8_AON. So 3V8_AON must be steady. Compare diode mode reading on it with good board.

Why don't you check left/right continuity, as above mentioned? I suppose that only few lines don't make good contacts.