820-4924-A no turn on, liquid damage

Sr. Robot

Member
Hi, got an 820-4924-A with extended liquid damage. No boot no charger light. Changed DC in Board no change.

PPBUS_G3H: 3.75v

PP3V42_G3H: 3.4v

PP5V_S5: 0v
 

2informaticos

Administrator
Staff member
" PPBUS_G3H: 3.75v
------------
27: 0.71v"
Are you sure?
PPBUS_G3H requires R7120 voltage!

Check all components surrounding U7100.
Also check solders and traces.
You may need to change U7100 and Q7130.
 

Sr. Robot

Member
Replaced U7100, now ive got green light but still no boot. Replacing Q7130 made no effect.

PPBUS_G3H: 1.5v

PP3V42_G3H: 3.4v

PP5V_S5: 0.9v

U7100 voltages:

1: 0v
2: 16.34v
3: 4v
9: 2.9v
12: 3.4v
13: 3.3v
14: 3.3v
15: 0v
17: 1.6v
19: 5.43v
20: 5.43v
27: 16.4v
 

Sr. Robot

Member
R7121/22 had high values so i replaced them.

U7100 voltages now:

1: 0v
2: 16.34v
3: 4v
9: 0v
12: 3.4v
13: 3.3v
14: 3.3v
15: 0v
17: Jumping from 2.8v to 18v
19: 5.43v
20: 5.43v
27: 16.4v
 
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