[SOLVED] 820-3302 no power

[lucas502]

Hi! I'm new here

Then:

iMac 21.5' A1418 (2012) - 820-3302 board
No power, no liquid, no corrosion
1 Led is on (S5 ok i belive)
I press the power button (also trigger SMC_ONOFF_L in J5020 pads) and nothing happens.

I don't have much experience with iMacs, but following the datasheet, I verified that these lines (all S5) are present and ok:

- PP12V_S5
- PP5V_S5
- PP3V3_S5
- PP3V3_S5_PCH_VCCSUS_USB
- PP3V3_S5_PCH_VCC_DSW
- PP3V3_S5_PCH_VCCSUS_HDA
- PP3V3_S5_PCH_VCC_SPI

When trigger SMC_ONOFF_L, the SM_SLP_S5_L react to 0v and returns to 3.3v.

I don't know what else to check now :/

Thanks!

 

[2informaticos]

First of all, welcome to the forum!

12V_S0_FET tries to appear at least?
Q7950 fails a lot on these boards, you should change it.

 

[lucas502]

First of all, welcome to the forum!

12V_S0_FET tries to appear at least?
Q7950 fails a lot on these boards, you should change it.

It was really the defective Q7950, it was not shorted but at the output (12V_S0_FET) there was only 2v.
Replaced and start normally

Thanks!

SOLVED

 

[2informaticos]

You're welcome!

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