820 3115, no green light

[Noguinfor]

whiling plug and unplug the mega safe, On PM_SLP_S4_L and PM_SLP_S3_L i have this ! https://drive.google.com/file/d/1kq_y91of8WX3ZjJKAe0OhZsKcTkvGmxv/view?usp=sharing Can i consider a pulse??

I already check this board with scoop 10 times looking components knockouts ... and Board have good aspect! I don't have more SMC if not, i change again for discharge!

 

[2informaticos]

Much better to trigger SMC_ONOFF_L (simulating power button with R5015/16) and check any reaction at the moment.

 

[Noguinfor]

SMC_ONOFF_L When i short the pads 3.42V gos to 0V!

i check PM_SLP_S4_L and PM_SLP_S3_L with oscilloscope and i don't have any pulse when i short the pads (R5015/16).

SMC_BC_ACOK measuring with oscilloscope and ORIGINAL CHARGER: https://drive.google.com/file/d/1DV2WhnrMhxXeyDlrknrVwCqS-xcZ9kXh/view?usp=sharing Without original charger i don't have this oscillations. I do not know if this information is useful but i try my best!

thanks

 

[2informaticos]

"SMC_BC_ACOK" needs to be steady 3V (or close value); no need o-scope to check it.
You must put SMC_ONOFF_L to ground for an instance only, like when pressing power button; do NOT maintain ground contact.

 

[Noguinfor]

I don't see any reaction! =(

i test with power supply and when i press the power button only consume 0.018A to 0.020A.

already replace SMC for one i know it's working!! and same history,,

could be PCH?

I really needed this board repaired. so I because insist a little more .. thank you

 

[2informaticos]

PM_PWRBTN_L reacts?
PM_RSMRST_L is steady 3V?
Do you have stable PPBUS_G3H and 3V42?

 

[Noguinfor]

PM_PWRBTN_L the only reaction i see it's the signal goes to 0v when i put SMC_ONOFF_L to ground for an instance.

PM_RSMRST_L = 0V

PPBUS_G3H and 3V42 are stable's! And in diode mode compare with a working board and shows same values! i still haven't green light with original charge only with fake!

i have a perfect working board with me. it's possible we know if PCH is working well with measure points ??

1 question we know PM_SLP_S4_L and PM_SLP_S3_L bought are pulsing, what does it mean?? i would like to understand!!

 

[2informaticos]

"PM_RSMRST_L = 0V"
It MUST stay high at 3V.
Post U7930 voltages.
Try to start in SMC bypass mode.

 

[Noguinfor]

U7939

pin1- PM_RSMRST_L = 0V
pin 2 - GND
pin3 - N.C - 3.3V
pin4 - S4_PGOOD_CT = 1.4V
pin5 - PP3V3_SUS_PWRCTL - 0.04V
pin6 - PP3V3_S5_PWRCTL - 3.3V

Don't star via SMC bypass mode!

 

[2informaticos]

So you miss 3V3_SUS.
Do you also miss PM_SLP_SUS_L?
This one should appear before start the board.

 

[Noguinfor]

No i have PM_SLP_SUS_L = 3.3V stable!

i noticed PP5V_S3 in diode mode i have 424v compare a working board i have 0.138v ... the problem can be here..already replace again this 2 components q7261 and q7260. i already check the rails and no one missing! can e a component fault??



thank you

 

[2informaticos]

Then check Q7820/22, you are missing 3V3_SUS...

 

[Noguinfor]

I do not know how to tell you this but while I was doing the measurements on Q7820 / 22, the comes to life without replace any component!!! i use a power supply to test boards, and when i see the current up to 900mA i'm WOW!!! This board repaired itself. in this type of situations what do you do ?? I have a lot of fear in these situations because the probability of coming back is high!

 

[2informaticos]

Check the solders for all the places you tocuhed before...

 

[Noguinfor]

Nice one Mr.Vali!!! Thank you for your patience and insistence. Without your help I would not be able to repair this mac. you are a legend! in addition to being repaired I learned from you .. thanks one more time