(347) 552-2258 [email protected]

[SOLVED]820-2330 no green light

Status
Not open for further replies.
F

Fizzl92

Member
U6915 has 16,6-16,7V at Pin 5. Is that to low. I tested the magsafe board with a Mainboard that has not even a CPU on it and it works.
 
F

Fizzl92

Member
ADAPTER_SENSE is 0,012V and i don´t have a oscilloscope. If i check for a short there i get OL. On a dead board with no cpu but green light i get 3.2-3.4V.
 
F

Fizzl92

Member
I got that Pin 2 and 5 of Q6920 are 0.00V. I guess that should be higher cause Q6920 is nMOS (open when gate is high). Pin 6 has >3V on it. Q6910 has 6,72V at pin 2 so 16V can pass from Pin 1 to Pin 6. But Q6915 is also opened. It has 8,12V at pin 5, so Pin 3 is connected to pin 4 = GND (multi meter beeps). If i disconnect the charger it is not beeping anymore , so i assume Q6915 is fine and the problem is the 8V at pin 5 of Q6915. R6913 - R6916 are all below 270k Ohm. U6915 has 8,13V at pin 1, 0V at pin 2, 0,012V at pin 3, 8,12V at pin 4 and 16,66V at pin 5. So if Pin 3 is normal (but it can´t be different as ADAPTER_SENSE is 0,012V as well and R6920 is fine) i would blame U6915 here.
 
F

Fizzl92

Member
Thank you for the confirmation. Is U6915 equal to u5000 of an 820-2850 (It has lover in and outputs, but partnumber is the same)? I don´t have the same board here to grab parts from it
 
F

Fizzl92

Member
Thank you for the answer. I saw that they are different. I just asked because eg. ISL6259 can work with different Voltages. Also i found different Datasheets and the Number which is written under "LM397" matches. My problem is that i can´t find this exact chip. I only have 820-3115, 2915, 2850, 2936, 2877 some Air and Retina boards avaliable.
 
F

Fizzl92

Member
LM397MF arrived, i soldered it in and now, finally, it works again. Seems like everything is fine now. Thanks for the great support!
 
Status
Not open for further replies.
Top