820-3115 green light, no fan/no power

[iClub]

yes.

 

[2informaticos]

Check/replace all surrounding components.

 

[iClub]

I have suspended the components around, it now shows 1.8V on the L7760 coil, but the fan does not turn.
I noticed that in the thermal camera the component u3900 gets hot.

 

[2informaticos]

Which voltages appear on the coils?
What about ALL_SYS_PWRGD?

 

[iClub]

All_SYS 51mV, no pulse.



Coils
Voltage:
L7770 1.5V
L7700 0.094V
L3895 2.54V
L7760 1.8V
L7520 0V
L7510 0V
L7550 0V
L7330 1.5V
L7030 12.6V
L7260 5.085V
L7220 3.32V
L7100 10mV
L7630 1.055V

diode mode:

L7770 0.349V
L7700 0.267V
L3895 0.527V
L7760 0.175V
L7520/L7510/L7550 0.005V
L7330 0.150V
L7030 0.460V
L7260 0.170V
L7220 0.156V
L7100 0.022V
L7630 0.018V

 

[2informaticos]

"L7100 10mV"
This voltage must appear before VCORE.

Post U7100 voltages; pins 15, 19, 20.

 

[iClub]

PVCCSA_EN 3.23V
PP5V_S0_VCCSAS0_VCC 5.084V
PP5V_S0 5.087V

 

[2informaticos]

Change U7100...

 

[iClub]

Replaces u7100, in tests the cooler does not move.

voltage values after replacement of u7100
Voltage:
L7770 1.5V
L7700 1.2V
L3895 2.54V
L7760 1.8V
L7520 0V
L7510 0V
L7550 0V
L7330 1.5V
L7030 12.6V
L7260 5.085V
L7220 3.32V
L7100 10mV
L7630 1.056

 

[2informaticos]

You still have a problem around U7100.
Check all components, solders and traces.

 

[iClub]

I have replaced the surrounding components, in tests it shows the same defect. The u7100 and the surrounding components are ok.

 

[2informaticos]

Maybe corroded trace, you STILL have a problem on that power supply.

 

[syslan]

I had the same problem that OP. I changed u7100 and nothing changed. Afterwrds I replaced Q7100 and it turned on, but, there is something that always keeps on harming the Q7100 .

it turns on, but when I connect the screen or the speaker the Q7100 breaks again.

When it was on , it booted ( Q7510-Q7520 = 0.75 V)


Any ideas?

 

[2informaticos]

Check/replace R/C7130...

 

[syslan]

I already checked and R7130 is fine and C7130 measures the same as the same capacitor from another good board

 

[2informaticos]

Did you check the capacitor in capacitance mode?
Is so dificult to change it?