Samsung NP300E5A-S02PL, MB: SCALA3-15/PETRONAS-15 - brak 3v oraz 5v

HotIce написав:czy ten zabieg mógł ją uszkodzić?

As far as I know the performed test should not harm the TPS chip or transistor Q58.

HotIce написав:Podałem napięcie i prąd od razu ustawił się na 200 mA, zauważyłem że mocno grzeje się podwójny mosfet Q58, kilka dni temu go sprawdzałem i był ok....

The damage on transistor Q58 may be caused by a bad solder joint on pin 10 of the TPS chip.

You can do this test again with a new TPS chip, but this time with the transistor Q58 removed from the board. Check whether 5V appears on the coil L513 or not.
Make sure that the solder joints on all pins of the TPS chip are fine before doing the test.

Usunąłem cewkę L512 i uszkodzony Q58 ale sytuacja wróciła do poprzedniego stanu czyli - po wciśnięciu PP pobór prądu 40mA a po kilku sekundach skacze na 200mA i wtedy mocno grzeje się przetwornica U24 a na L513 nie pojawia się 5v jest 0v.

Also remove the transistor Q509 from the board and check whether the chip U24 still heats up after pressing to the power button.

matic написав:Also remove the transistor Q509 from the board and check whether the chip U24 still heats up after pressing to the power button.

Niestety po usunięciu Q509 nadal grzeje się U24

Remove the chip U24 from the board.
Inject 3.3V from the laboratory power supply to the power rail "P3.3V_MICOM" (solder the wires to the capacitor C480). What electrical current flows from the laboratory power supply in this case?

Then also inject 5V from the laboratory power supply to the power rail "P5.0V_STB" (solder the wires to the capacitor C6518). What electrical current flows from the laboratory power supply in this case?

matic написав:Remove the chip U24 from the board.

Inject 3.3V from the laboratory power supply to the power rail "P3.3V_MICOM" (solder the wires to the capacitor C480). What electrical current flows from the laboratory power supply in this case?

Then also inject 5V from the laboratory power supply to the power rail "P5.0V_STB" (solder the wires to the capacitor C6518). What electrical current flows from the laboratory power supply in this case?

W pośpiechu nie zauważyłem żeby zdjąć U24 i podłączyłem 3.3 oraz 5v:
- wynik dla 3,3 : po podłączeniu 15mA a po kilku sekundach spada do 3mA
- wynik dla 5v : po podłączeniu 17mA a po kilku sekundach spada do 7mA

Czy powtarzać wynik z usuniętym U24?

HotIce написав:Should you repeat the result with the removed U24?

There is no such need.

Try to replace the transistors Q58, Q509 and the chip U24 with a new ones one more time. As for the chip U24 you can use the chip TPS51125 or RT8223P.
Make sure that the solder joints on all pins of the chip U24 are fine.
Connect the board to the laboratory power supply set to 19V and the current limit to 0,2A.