A1466 no power

[mon2]

re: 820-3437

Hi. Have an A1466 with no power. Green / orange light on magsafe adapter ok.

PPBus ok at 8v6
3v42 ok
3v3 ok
Missing 5v0
Missing vcore 1v02

Have removed the battery, no difference.

Vcore cap resistance at 0.312 ohms on vcore rail which seems low ( will confirm again on Monday).

Concerned that enable for the 5v0 rail is low. Yet the right side of the shared dual regulator is ok and able to produce the 3v3 rail.

The 5v0 enable is mated with an AND gate which is low input / output, not good as it should be '1'.

This AND gate is fed to the SMC?

Could the SMC be damaged?

What is the remedy for the SMC? Replacement? AliExpress?

Will review the schematics again to confirm the power on sequencing. Aside from what appears to be a shorted cap on vcore, no liquid damage indicator triggered.

Any ideas on how to troubleshoot this one?

Is the vcore rail supposed to be this low on resistance?

Thanks.

[piernov]

Re: A1466 no power

https://logi.wiki/index.php/Resistan...List#Haswell-U

You should know by now that you have to go through the list of power rails and check which ones have voltage, which ones don't have voltage and if they are shorted to ground…