820-2523 wont turn on motherboard have all power rails except for so rails

[djpat1974]

Hi I have an 820-2523 with these rails working
PPBUS_G3H =12.61
PP3V42_G3H =3.4
PP5V_S3 =5.v
PP3V3_S5 =3v
am missing my so rails they read 0.0v except for L7770 I get 1.06v with greenlight at MagSafe original one please advise maybe something a,m missing thanks.

 

[dukefawks]

Are you using a 85W charger? Check if ADAPTER_EN is high.

 

[djpat1974]

you mean SMC adapter_en is 3.3v

 

[djpat1974]

SMC adapter_en is 3.3v

 

[smiba]

I assume PP5V_S5 is around 5V?

Is P5VS3_EN high?
What is the voltage of PP3V3_S3?

 

[dukefawks]

You are pressing or shorting the power pads? These boards do not auto power on.

 

[djpat1974]

hi PP5V_S5 is around= 5V P5VS3_EN high =0.0v PP3V3_S3=0.0v

 

[djpat1974]

hi duke I short the pads but from what smiba ask me for i found missing hi PP5V_S5 is around= 5V P5VS3_EN high =0.0v PP3V3_S3=0.0v

 

[djpat1974]

hi if p5vs3_en is low that mean PM_SLP_S4_L is 0.0v

 

[dukefawks]

PP5V_S5 is pretty much mislabeled in the diagram as it comes from 5V_S3. You say in your first post: PP5V_S3 =5.v, if that is true the power sequence is starting or is this a wrong measurement?

What is the history of this board?

 

[djpat1974]

yes that is and mislabel water damage the customer before I clean it and try to fix it now it is in my lap to be fix

 

[dukefawks]

You say in your first post: PP5V_S3 =5.v, if that is true the power sequence is starting or is this a wrong measurement?

I had no answer to that....

Also resistance to GND on PP3V42?

 

[djpat1974]

sorry for that PP5V_S3 =5.v is working at 5v and PP3V42 to gnd is 2.300 ohm and diode mode 0.289

 

[dukefawks]

So just to be 100% sure here, there is 5V present on L7220? If that is the case the board is starting the power cycle and more S3 rails should be present. Also PM_SLP_S4_L should be present.

 

[djpat1974]

Hi dukefawks what you are saying is true but 5v is on l7220 but PM_SLP_S3_L and PM_SLP_S4_L are missing and that i believe is my problem

 

[dukefawks]

PM_SLP_S4_L cannot be missing as it is the enable for 5V_S3