Lenovo G40-50 Aclu5/aclu6 wont turn on

[maurovalero]

I was working well with him, one day he turned off he did not turn on, checking it I found that the pu401 heats up when the charger is connected, I already replaced it but the fault persists remove the capacitor that is close to the pj401 and did not cause the short.
the pu401 SY8206BQNC, is short but when removing the pad pj401 disappears the short but the pu401 is the source of 3v.

pl401 pl402 no voltaje, capacitors near of pu402 whit voltaje 20, 3.2 5.6

[Techtiger]

Re: Lenovo G40-50 Aclu5/aclu6 wont turn on

PJ401 which side is short to GND , test all pins of PU402 except pin 9 for Voltage

[maurovalero]

Re: Lenovo G40-50 Aclu5/aclu6 wont turn on

Thx for reply
1- no voltaje
2- no voltaje
3- no voltaje
4- no voltaje
5- 3.2v
6 - 2.8v
7- 5v
8- 20v
thats values is whit open pad pj401, short to ground is in top
pu401 inicially pu401 was warming but now the source don have consum
pu401
1- no voltaje
2- no voltaje
3- no voltaje
4- no voltaje
5- 2.1
6 - 2.1v
7-
8- 20v

[Techtiger]

Re: Lenovo G40-50 Aclu5/aclu6 wont turn on

Remove the jumper PJ402 PJ406 check the resistance to GND both side of PJ402 pj406
After test pin 85 of UE1 SIO chip EC ON 3.3V page 44, PU401 IC pin 1is connected with 2 resisters 1 cap and a Diode test for any shorts on those components
PU402 pin 1 connected with 2 resisters 1 cap and a Diode test for any shorts on those components
This chip is getting 19+ LDO is ok but no +3VALW +5VALW you need EC ON to enable this chip

[maurovalero]

Re: Lenovo G40-50 Aclu5/aclu6 wont turn on

Thanks for answering, none of the components were short, you have any other suggestions.
I did the tests with pj402 pj406 pj401 pj402 open
When I close PJ402, the indicated capacitor is bridged to the ground on both ends, I remain attentive.

[mcplslg123]

Re: Lenovo G40-50 Aclu5/aclu6 wont turn on

Thanks for answering, none of the components were short, you have any other suggestions.
I did the tests with pj402 pj406 pj401 pj402 open
When I close PJ402, the indicated capacitor is bridged to the ground on both ends, I remain attentive.

but you didnt mentioned reistance of both pads of PJ402-one of the pads is likely to be short.

[maurovalero]

Re: Lenovo G40-50 Aclu5/aclu6 wont turn on

but you didnt mentioned reistance of both pads of PJ402-one of the pads is likely to be short.

srry i did wrong pad is pj403 in short to ground

[mcplslg123]

Re: Lenovo G40-50 Aclu5/aclu6 wont turn on

If you have lab supply, then inject 1V with high amps on the shorted side of PJ403 and see what becomes hot.