• Lenovo Z51-70 LA-C281P nie włącza się

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This topic is marked as ARCHIVAL. Please only reply if your message contains the solution (Terms and Conditions p. 12.1).

#1 Lenovo Z51-70 LA-C281P nie włącza się


by Stocun 18 July 2017, 09:25
Mam lenovo Z51-70 z płytą LA-C281P, laptop nie reaguje na włącznik, brak napięć 3v3 i 5v, brak schematu, proszę o pomoc.

Re: Lenovo Z51-70 LA-C281P nie włącza się


by Google Adsense [BOT] 18 July 2017, 09:25

#2 Re: Lenovo Z51-70 LA-C281P nie włącza się


by matic 18 July 2017, 12:14
Hello!

Check datasheets of chips in QFN package, and try to find standby DC/DC switching controller.

Post marking of this chip here.

#3 Re: Lenovo Z51-70 LA-C281P nie włącza się


by Stocun 18 July 2017, 13:35
EM5209

VIN1 0V
ON1 0V
VBIAS 0V
ON2 0V
VIN2 0V
VOUT2 0V
CT2 0,22V
GND 0V
CT1 1,6V
VOUT1 0V

#4 Re: Lenovo Z51-70 LA-C281P nie włącza się


by matic 19 July 2017, 11:38
EM5209 is load switch.
I think it should be another chip which controls DC/DC standby converter.

#5 Re: Lenovo Z51-70 LA-C281P nie włącza się


by Stocun 20 July 2017, 13:02
R14VB ?
RJ4UC ?

Image

#6 Re: Lenovo Z51-70 LA-C281P nie włącza się


by przemko21 20 July 2017, 23:39
Sprawdź rezystancje na cewkach.
Układy przetwornic zasilane? występują jakieś napięcia?
Jeżeli nie to sprawdź czy charger jest zasilany.

#7 Re: Lenovo Z51-70 LA-C281P nie włącza się


by Stocun 26 July 2017, 09:05
Rezystancja PL402 3kΩ
Rezystancja PL404 12kΩ
Obydwa układy są zasilanie 19V

Image

#8 Re: Lenovo Z51-70 LA-C281P nie włącza się


by matic 26 July 2017, 10:52
These two chips could be standby DC/DC switching controllers.

Which KBC chip is on the board?

#9 Re: Lenovo Z51-70 LA-C281P nie włącza się


by Stocun 26 July 2017, 13:09
NPCE288NA0DX

#10 Re: Lenovo Z51-70 LA-C281P nie włącza się


by przemko21 3 September 2017, 16:02
Rozumiem,że na cewkach PL402 i PL404 nie ma napięcia 3.3V oraz 5V?

#11 Re: Lenovo Z51-70 LA-C281P nie włącza się


by matic 3 September 2017, 19:26
Measure voltages to ground on pins 111 and 125 of KBC chip.

#12 Re: Lenovo Z51-70 LA-C281P nie włącza się


by cezaro2 4 September 2017, 06:15
Temat mocno odgrzewany od ponad miesiąc martwy, także nie wiem czy jest jeszcze aktualny.
Jeśli nadal temat aktualny to niech kolega Stocun napisze:
- czy może przetwornica PU401 wyczuwalnie się nagrzewa
- jaka jest rezystancja na 5 nodze PU401 (tam gdzie jest wystawiane 3,3V-zdjęcie)
- jakie napięcie mamy na 1 nodze PU401

Re: Lenovo Z51-70 LA-C281P nie włącza się


by Google Adsense [BOT] 4 September 2017, 06:15
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