820-00430-A iMac A1418 imac2015

lincev

Member
hi friends, I have received this equipment and I have been able to observe that it had some corrosion in the area of the image that I attached, I have cleaned it well, I have not observed anything strange but only 2v reaches the power pad pins, I need your help. thanks a lot

Captura de pantalla 2024-05-13 a las 10.43.17.png
 

lincev

Member
oh sorry i'm talking about the pins of the power button connector on the power supply

Edit: when plug power cord I can't see any led green
 

lincev

Member
Q6970
1 PP12V_S5=0v
2 PP12V_S5=0v
3 PP12V_S5=0v
4 FET_EN_P12V_S5=0v
5 PP12V_G3H=12v

sorry I edit title the model is 820-00430-a
 

2informaticos

Administrator
Staff member
"1 PP12V_S5=0v
2 PP12V_S5=0v
3 PP12V_S5=0v"
Any reason to check that on 3 pins tied together?
Use the logic and save time.

Now post U6970 voltages.
Just in case, check diode mode to ground at 12V_S5.
 

lincev

Member
U6970
1 PP12V_G3H= 12v
2 SMC_PM_G2_EN=0v
3 UNCONNECTED
4 GND
5 PP12V_G3H= 12v
6 PP12V_S5= 0v
7 FET_EN_P12V_S5= 0v
8 PM_EN_REG_P3V3_S5=0v
9 GND


12v_S5 mode to ground value 1866
 

lincev

Member
hi thanks

values:

U6900
1 P3V42G3H_FB= 0,75v
2 PP3V42_G3H_REG_R= 2,10v
3 P3V42G3H_BOOST=4,68v
4 P3V42G3H_SW=1,98v
5 GND
6 PP12V_G3H= 12v
7 UNCONNECTED
8 P3V42G3H_SHDN_L=3,58v
9 GND
 

lincev

Member
Yes, sorry, you are right, I checked the references and they are both LT3470AED,

new values (very similar to last time):

U6900
1 P3V42G3H_FB= 0,75v
2 PP3V42_G3H_REG_R= 2,10v
3 P3V42G3H_BOOST=4,68v
4 P3V42G3H_SW=1,92v
5 GND
6 PP12V_G3H= 12,01v
7 UNCONNECTED
8 P3V42G3H_SHDN_L=3,57v
9 GND
 

2informaticos

Administrator
Staff member
Remove L6901 and inject 3-3.5V on its pad 2.
Use an IR camera and look if something gets more hot than expected.
 

lincev

Member
I have been able to observe D1900 diode very hot, but it has been replaced with a new one and when I inject 3v it heats up again, is this normal?
 

2informaticos

Administrator
Staff member
Replaced why, don't you know how to test it???

Check diode mode to ground at 3V3_G3_RTC.
Connect new coin cell and post D6901 voltages; power from wall disconnected.
 

lincev

Member
I thought it would be better to replace it......

PP3V3_G3_RTC_SW= 790 value

D6901 ? I can't see it, I have APPLE IMAC A1418 LATE 2015 J117 MLB 820-00034 / 820-00430-a 051-00081 SCHEMATIC
 
Top