iPhone 6 Logic board not booting. DCPS shows 200 mA draw

Did you check ALL of the PMIC outputs or just the main ones? A faulty subsystem can pull the whole system down as well and it is often overlooked. If they all check out, then check the main subsystems that aren’t powered by the PMIc, such as MESA,CHESTNUT, BACKLIGHT. Then check the I2C lines to insure they are balanced and within range and take a look at the PMIC Reset lines (those that can be probed) to see if the problem is there.

Finally, check the BBPMU outputs as well as a damaged BB system will impede the phone from booting.

Also, what areas of the board were more corroded, that could give you some clues about where the damage actually is.

Esta resposta foi útil?

Sim Não

Pontuação 2

4 comentários:

Update:

PP 1V8 SDRAM rail reads 0.52 V

???

1 de fev de 2019 por Hama

Check that power rail with the phone unpowered in diode mode to see what reading you get. There may be a partial short that you will need to elucidate.

1 de fev de 2019 por Minho

Found the shorts:

Backlight driver —> 0.18 A

U5302_RF —> 0.02 A

Both are removed.

No booting ( from zero goes to 0.12 A & repeat itself)

DFU recovery on iTune recognizes the board but haven’t gone farther. (Did not recover). Trying not to loose data.

?

6 de fev de 2019 por Hama

PP 1V8 SDRAM. Ow reads correctly 1.8

6 de fev de 2019 por Hama

Adicionar um comentário

Check that power rail with the phone unpowered in diode mode to see what reading you get. There may be a partial short that you will need to elucidate. — Minho
Found the shorts:

Backlight driver —> 0.18 A

U5302_RF —> 0.02 A

Both are removed.

No booting ( from zero goes to 0.12 A & repeat itself)

DFU recovery on iTune recognizes the board but haven’t gone farther. (Did not recover). Trying not to loose data.

? — Hama