(347) 552-2258 help@rossmanngroup.com

820-02098-07 - 5V 1A / liquid damage

quasimodo

quasimodo

Member
Hey guys,

got a m1 14" here. coffee damage. amp meter shows 5V 1A

my readings:

PPBUS_AON: 7V (.450 diode mode reading)

PP3V8_AON: 2,27V (diode mode peeps, 2,7 ohm reading, cant really find a short there?)
PP5V_S2_MAIN: 0V (.384 diode mode reading)


backlight area looks bad.


can you help me out?
 
2informaticos

2informaticos

Administrator
Staff member
7V at PPBUS_AON with battery connected?
Did take diode mode reading at 3V8_AON disconnecting charger and battery?
 
quasimodo

quasimodo

Member
these readings from usb-c connected charger. (140w)

7V without battery connected. just charger.

diode mode readings -> without nothing connected. just the board.
 
2informaticos

2informaticos

Administrator
Staff member
Remove F5200/1 and check C5250 voltage.
If still low, check all resistors and traces related with U5200.
 
2informaticos

2informaticos

Administrator
Staff member
OK, so U5200 area is good.
You have problems with some other secondary power supply derived from PPBUS_AON.
Compare diode mode to ground reading with another good board; check in both directions.
 
quasimodo

quasimodo

Member
no other good board here.

there is a problem with PP3V8_AON. multimeter beeps. theres a short but cant detect it?

the area around q5800/20/40...?
 
2informaticos

2informaticos

Administrator
Staff member
Something should be detected with thermal camera, injecting 3-4V there.
Remove CPU heatsink; M1 is the first suspect...
 
You must log in or register to reply here.
Top