iMac 21.5" Mid Late 2015 820-00430-A no clue

[No-Clean]

PP1V05_S0 is 0.005 and PP1V5_S0 is 0v

Power rails missing are PP1V2_S3_DDR, PP3V3_S0, PP1V5_S0 and PPCPUVCC_S0_CPU

 

[2informaticos]

Are you sure???
You just confirmed 1.2V at L7310 before...

 

[No-Clean]

yes sorry

PP1V2_S3 and PP1V2_S3_DDR are present but not PP3V3_S0, PP1V5_S0 and PPCPUVCC_S0_CPU ​

 

[2informaticos]

Post U8400/500 voltages.

 

[No-Clean]

U8400 1-3.3v 2-3.3v 3-3.3v 4-5v 5-0v 6-3.3v 7-3.3v 8-0v 9-0v 10-0v 11-0v 12-11v 13-3.3v 14-3.3v

U8500 1-3.3v 2-3.3v 3-3.3v 4-3.3v 5-3.3v 6-3.3v 7-G 7--14-3.3v

 

[2informaticos]

Looks like missing PM_SLP_S3_L; check that.
Also check REG_P1V2_S3_PGOOD at U7300.
Be sure =PP3V3_S4_PWRCTL and R7340 OK.

 

[No-Clean]

PM_SLP_S3_L present 3.3v ​

PM_PGOOD_REG_P1V2_S3 3.3v at U7300 R7340 is 19.49k checking real value now as I dont see that resistor on the schematic

 

[No-Clean]

Whats strange is that

R7340 is ok at 19.49k but ​

PM_PGOOD_REG_P1V2_S3 is 3.3v not 1.2v

 

[2informaticos]

Mmmm, I just saw that in fact you didn't post any voltage for pins 8/9/10 of U8500.
I was reading values from U8400 instead.

Do you get PM_EN_S0?

 

[No-Clean]

PM_EN_S0 is 3.3v at U8500 ​

 

[No-Clean]

PM_EN_S0 is 3.3v at U8600 but ​

PM_EN_FET_P3V3_S0_R at U8600 is 0.013v

 

[2informaticos]

Yeas, because missing PM_PGOOD_REG_P1V05_S0 signal; which is same as REG_P1V05S0_PGOOD.
PM_EN_S0 presence suppose to get some S0 voltages controlled by this signal.
Check PM_EN_FET_P3V3_S0, PM_EN_FET_P12V_S0 and PM_EN_FET_P5V_S0