820-3115 green light, no fan/no power

iClub

Member
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.
 

iClub

Member
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
 

iClub

Member
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
 

iClub

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

syslan

Member
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?
 

syslan

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