Component identification

[reaper57]

Hi, I'm trying to fix a laptop that doesn't want to power on and I suspect what might be causing the problem, but I can't find a datasheet for it. A picture of the component is in the attachments. I've also included a picture of the motherboard model.
Thank you in advance!

[selldoor]

Re: Component identification

Not looked for it yet but the component with a Q on it could be a fuse?

[trebo]

Re: Component identification

Check this out,
https://cdn.badcaps-static.com/pdfs/...7cd1a0ca35.pdf

[dj_ricoh]

Re: Component identification

that Q component maybe a diode.

its connected from + to ground and you only do that when you want to protect from short.

as for the component in the red square make a picture and draw how everything its connected. Drain Source and gate.

you can pin point what is not working if you start to draw by hand and see where is stops.

my money its on that fet with no voltage on gate and a small chance that the Q component its a diode and its open with ground and it stops the + line to power up.

lift it up and see what happens.

[reaper57]

Re: Component identification

The component with a Q on it is indeed a fuse, but that's not what I was asking about. On the N-channel Mosfet I get 20V input on all of the pins on one side and 0.9 on all of the pins on the other side. So if it's used for the CPU power it should be ok right? If this is true can someone point me to the standby voltages on the motherboard?
Thanks!

[reaper57]

Re: Component identification

that Q component maybe a diode.

its connected from + to ground and you only do that when you want to protect from short.

as for the component in the red square make a picture and draw how everything its connected. Drain Source and gate.

you can pin point what is not working if you start to draw by hand and see where is stops.

my money its on that fet with no voltage on gate and a small chance that the Q component its a diode and its open with ground and it stops the + line to power up.

lift it up and see what happens.

I think that it's a fuse, since it's reading 0 ohms in both directions.

[tibd]

Re: Component identification

N-channel mosfet, best way to check is to take off board and check. The DS voltage follow is controlled/ opened by gate(G) voltage . Not always possible to test on board specially applying the voltage to G to see if it opens drain D to source S.

[paulstef]

Re: Component identification

The component with a Q on it is indeed a fuse, but that's not what I was asking about. On the N-channel Mosfet I get 20V input on all of the pins on one side and 0.9 on all of the pins on the other side. So if it's used for the CPU power it should be ok right? If this is true can someone point me to the standby voltages on the motherboard?
Thanks!

On what pins you get what voltage?

Since gate and source are on the same side and you measured from all pins of each side to ground the same voltage I'd say that this MOSFET was in the OFF state when you measured it. The best though is to measure from gate to source.

[Djosla]

Re: Component identification

Q is fuse...this is your problem:

https://www.badcaps.net/forum/showpos...79&postcount=3

[newtothis]

Re: Component identification

Q is fuse...this is your problem:

https://www.badcaps.net/forum/showpos...79&postcount=3

That is a broken link, And its already been established that its a fuse

[budm]

Re: Component identification

For that MOSFET to be on, the Vgs has to be at least 1.2VDC (the Vgs-threshold is 1.2V min).

[rievax_60]

Re: Component identification

If that MOSFET is used to switch the AC adapter voltage to he VBAT rail, its control circuit usually wont try to turn it on if there is a short to ground on the VBAT rail. Also check the Gate to Source resistance while no power is supplied.

[tata123]

Re: Component identification

Its a SMD N-CHANNEL MOSFET.

[dj_ricoh]

Re: Component identification

Find the QFN that is near .

Maybe you get lucky and find the charging Ic.

There you will see whats wrong.