Lenovo G50-80 Missing component

[tsiga]

Hi!
I have lenovo g50-80 (ACLU3/ACLU4 UMA NM-A362). The mootherboard is water damaged. One little component is missing.
when i plug dc, the machine turn on automatically but no boot logo or anything.
Can anyone identify this component?
Any advice would be much appreciated Thanks!

[mcplslg123]

Re: Lenovo G50-80 Missing component

Do you expect someone to respond without attaching the photos???

[tsiga]

Re: Lenovo G50-80 Missing component

LOL sry. In turn i attached.
Picture 1
Picture 2

[jasko_jacker]

Re: Lenovo G50-80 Missing component

No component in place on those pads. One pad totally corroded , see if it's connected with other pad and replace connection.

[khaahk]

Re: Lenovo G50-80 Missing component

From another picture shows resistor, value unknown.

[R_J]

Re: Lenovo G50-80 Missing component

I found a schematic for a NM-A272, on page 46 it shows Q25 with one end of R149 (150K) connected between +20vsb and D of Q25
Panjit semi shows the 2n7002KW with a marking K72 so it looks like the same fet

[tsiga]

Re: Lenovo G50-80 Missing component

#jasko_jacker#
Yes, the pad fully corroded. there was a resistor but can't measure.

#khaahk#
Thank you!

#R_J#
Thank you, I watched this schematic before write post. These two motherboard is different.
I measured Q25 (Q27 in schematic) drain leg this pin connect to Q24(3VS) gate leg.
If my assumption is wrong, there will be more damage in MB.

[jasko_jacker]

Re: Lenovo G50-80 Missing component

Try with small hight value potentiometer.

[lovendhra]

Re: Lenovo G50-80 Missing component

Hey Tsiga whatever happened to that water damaged laptop i think mine has a similar problem. as soon as you plug in power connector it comes on. and nothing on the screen its blank.. i have similar corrosion around q25 area..

[emestee]

Re: Lenovo G50-80 Missing component

The first place to start diagnosing self-start problems is the power button and whether the corresponding EC pin is shorted to ground...