Hello friends , thinking was easy to fix...but
Got this Acer 5741 5742 LA-5892p that didn't power on.
When charger is plugged ,got only 7v at PR351 = P3..the 2 first mosfet are ok but i got 18.7v at the 2 gate...it's P-channel so must be 8-10v..
To get the right gate voltage Pq63 must be ON to allow the rule of voltage divider..but it's off = PQ63 pin1 =18v.
PACIN = 3v and same at first pin of PR371...but 0v at pin 2.
If i got 3v at side 2 of R371 so PQ 59/PQ 63 will be ON and the voltage divider will be ok...but no 3v.
Testing PQ 56/ PQ 58 / PQ 59 /Pq 63 for short and they are all OK.
Testing PU17 : no voltage at DCIN pin 24...no voltage at the enable pin
To get DCIN PQ 55 must be ON than the gate of PQ 54 will be realize fron the voltage divider and the voltage pass from P3 to DCIN...but it's off.
PQ 55 is off because no FSTCHG ( who supply the enable pin too of pu17 )
So..direction 3/5 v always....no short and no voltages!!..so the io is not supllied...so no FSTCHG.
Changing pu16 still the same.
I m so confused here..any others ideas
Thank you
Got this Acer 5741 5742 LA-5892p that didn't power on.
When charger is plugged ,got only 7v at PR351 = P3..the 2 first mosfet are ok but i got 18.7v at the 2 gate...it's P-channel so must be 8-10v..
To get the right gate voltage Pq63 must be ON to allow the rule of voltage divider..but it's off = PQ63 pin1 =18v.
PACIN = 3v and same at first pin of PR371...but 0v at pin 2.
If i got 3v at side 2 of R371 so PQ 59/PQ 63 will be ON and the voltage divider will be ok...but no 3v.
Testing PQ 56/ PQ 58 / PQ 59 /Pq 63 for short and they are all OK.
Testing PU17 : no voltage at DCIN pin 24...no voltage at the enable pin
To get DCIN PQ 55 must be ON than the gate of PQ 54 will be realize fron the voltage divider and the voltage pass from P3 to DCIN...but it's off.
PQ 55 is off because no FSTCHG ( who supply the enable pin too of pu17 )
So..direction 3/5 v always....no short and no voltages!!..so the io is not supllied...so no FSTCHG.
Changing pu16 still the same.
I m so confused here..any others ideas
Thank you
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