820-4924 no green light

hascanio

New member
Hi, i have this board with no green light.
The signal SMC_RESET_L is 0V (pulling the SMC doesn't change)
CHGR_CSO_R_P is 12,26V
U5110 :
pin 1 : 3.4V
pin 3 : 3.4V
pin 4 : 0,2V
pin 5 : 0V
pin 6 : 3.4V
pin 7 : 3.4V
pin 8 : 3.3V
Things done :
- changed U5110
- changed SMC
- checked res R5100 (if i short pin 1y2 green light turn on)

Thanks
 

2informaticos

Administrator
Staff member
"checked res R5100 (if i short pin 1y2 green light turn on)"
This is how you've checked it???
Does it have 100K?

Pin 4 voltage isn't good; change C5101.
Be sure no corrosion around U5110.

"The signal SMC_RESET_L is 0V (pulling the SMC doesn't change)"
That is the last test you should think off.
Isn't more easy to remove U5110 and R7100 first???
 

hascanio

New member
I already done many tries i haven't told you :
C5101 was good but i had already changed it
R5100 is 100K pulled, 45K in place (already changed)
No corrosion around U5110
R7100 already checked
Impedance (diode mode) checked in all U5110 pins.
All checked obviously before changing SMC
P.s. no me regañes... :)
 
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2informaticos

Administrator
Staff member
"R7100 already checked"
I said remove it; is the only way to discard U7100 pulling down SMC_RESET_L.

Do you get correct SMC_RESET_L when remove U5110?

No intento regañarte, si no enseñarte como ganar tiempo.

I also mentioned to remove U5110; did that?
If SMC_RESET_L goes high then, change U5110.
 
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hascanio

New member
So, removing U5110 green light turn on, but i have no other replacement (i had changed it !) to try.
Do you know if i can find the same reference in another board ?
 

2informaticos

Administrator
Staff member
C5101 sets the delay for SMC_RESET_L.
Pin 4 voltage should rise above 2V.
Re-check all solders and traces on the U5110 area.

Test the machine disconnecting keyboard/trackpad.
 

hascanio

New member
No problems around U5110, all voltages, less than pin 4 and 5 are good and i am doing all tries out of notebook, nothing connected......and now ?o_O
 
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hascanio

New member
Yes of course. But i found a solution (not definitive) : i put the U5110 without soldering pin 4 y 5. Board boot up and work perfectly but i had to change also U7501 because S5 rails didn't turn on. Now i have to solder pin 4 y 5 of U5110 to see if all will return to normality.
 

2informaticos

Administrator
Staff member
If pin 5 is not soldered, SMC_RESET_L timing is not respected.
SMC may not work properly, nor even tunrs on the board sometime.
 

hascanio

New member
Well i know is not a solution but that was a dead board and i already sell a new one to the owner, so.....i will use it for experiment or replacement part. Thank you as usual for your support ;)
 
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