HP 250 G3 - Sudden , no power (Not even light) LA-A992P Rev:1.0

[Acnologia]

HP 250 G3 - Sudden , no power (Not even light) LA-A992P Rev:1.0

As the laptop was working just fine , without any problems , it suddenly came off.

The charging light that you see on the HP laptops, that you have plugged the DC wasn't there .
Tried removing ,CMOS,RAM etc etc. checked everything.

Now the laptop it's brain cold , with the only chip that is heating is the PQ101 (MOSFET MDU1512) which is near the DC-Jack connector.

The jack connector takes 19.5volt all good so charge is coming INSIDE the laptop, but when you press the power button nothing happens, we don't have a single light..

As soon as you plug in the DC the only chip as i said is heating up is the MOSFETMDU1512.

Does anyone have any thoughts ?

I am attaching the schematic.

[Acnologia]

Re: HP 250 G3 - Sudden , no power (Not even light) LA-A992P Rev:1.0

I don't know where else i should start looking,i also checked the connection between the power button ,to the power board connector, and it beeps so ,it's with clear bridge,nothing broken there.

So that it doesn't turn on , should be something else.

No liquid was dropped,sudden death.

[Techtiger]

Re: HP 250 G3 - Sudden , no power (Not even light) LA-A992P Rev:1.0

What is the Voltage on PR103 & pin 4 of the PQ101?

[Acnologia]

Re: HP 250 G3 - Sudden , no power (Not even light) LA-A992P Rev:1.0

What is the Voltage on PR103 & pin 4 of the PQ101?

PQ101 - Has been tested in resistance as well.
With limit 2M (Ωhm) one side has 0,4 and the other side PIN4 has 0 and the rest have 1.7 resistance and climbing.

The voltage on the PR103 has been 0.55 and raising and dropping with limit the Value 2 , of the multimeter .

[Techtiger]

Re: HP 250 G3 - Sudden , no power (Not even light) LA-A992P Rev:1.0

so its' 002 Ohms you have a short , remove out of the bed PQ101 N channel fet test S D G Ohms after test again PR103 with out PQ101 & power, test PQ103 PQ104 also

[Acnologia]

Re: HP 250 G3 - Sudden , no power (Not even light) LA-A992P Rev:1.0

so its' 002 Ohms you have a short , remove out of the bed PQ101 N channel fet test S D G Ohms after test again PR103 with out PQ101 & power, test PQ103 PQ104 also

https://youtu.be/Gm4iWjogjzs

[Techtiger]

Re: HP 250 G3 - Sudden , no power (Not even light) LA-A992P Rev:1.0

You you have checked the pads with out the fet Reading is OK no check the Removed MOSFET Ohms & the PR103 Ohms with out removing

[Acnologia]

Re: HP 250 G3 - Sudden , no power (Not even light) LA-A992P Rev:1.0

You you have checked the pads with out the fet Reading is OK no check the Removed MOSFET Ohms & the PR103 Ohms with out removing

Thanks for all the help .

I have tested so far :

The REMOVED MOSFET PQ101 the 4 legs , show 0,49ohm.

Without removing the PR103 ,with black on ground ,shows in both sides no value ,only in the beep mode with ground to a random hole, beeps in both sides.

[Techtiger]

Re: HP 250 G3 - Sudden , no power (Not even light) LA-A992P Rev:1.0

0.49 Ohm PQ101 it's too low did you test it correctly (S D G) put the multimeter on continuity mood & test again PR103 what value you get

[Acnologia]

Re: HP 250 G3 - Sudden , no power (Not even light) LA-A992P Rev:1.0

0.49 Ohm PQ101 it's too low did you test it correctly (S D G) put the multimeter on continuity mood & test again PR103 what value you get

I believe i am doing it correctly.

Here is the video :
https://www.youtube.com/watch?v=JPY-q5VKF1U

Here are some pictures.

[Techtiger]

Re: HP 250 G3 - Sudden , no power (Not even light) LA-A992P Rev:1.0

there is a clear short on the MAIN line do you have a power LAB ? if not remove PR103 & test which side( Dc jack or +B) is short to GND

[classicandy]

Re: HP 250 G3 - Sudden , no power (Not even light) LA-A992P Rev:1.0

I believe i am doing it correctly.

Here is the video :
https://www.youtube.com/watch?v=JPY-q5VKF1U

Here are some pictures.

Clearly, you have a short on the B+ line like @techtiger said.....

If you don't have a Power LAB [30V DC Power Supply Machine], I have a method that works very well for me but there are somethings to do as a precautionary measure.

Remove these before you proceed with the steps below:
PLW2
PLH2
PLZ2
PLV2
PLV3
(Just a precautionary measure)

Steps:

- Get 3 charged Li-ion battery Cells connected in series so you have approximately 12v

- connect a piece of wire to the positive end of the first cell

- connect another piece of wire to the negative end of the last cell

- Connect the negative wire from the cell to any GND point on the motherboard. (You can tie it to one of the screw holes on the board, i.e Near SD card port)

- Connect the positive wire from the cell to probably a needle and use the needle to touch PR103

- Important part, take note, the shortened component is going to burn out or get heated up. Once you see the heated component, remove and replace. You should be good to go


The reason why I suggested removing those Induction Coils is because current @12v can escape through them and probably damage the CPU or Discrete Card (in your case).

Believe me, I've lost an 8th Gen CPU to this........


I'm opened up to better ideas in case others feel this method is unsafe

[mcplslg123]

Re: HP 250 G3 - Sudden , no power (Not even light) LA-A992P Rev:1.0

If you want to repair laptops, investing in proper tools is a must. There can be no alternative to lab psu. This battery method will work but its not viable for regular repair job.

[Acnologia]

Re: HP 250 G3 - Sudden , no power (Not even light) LA-A992P Rev:1.0

there is a clear short on the MAIN line do you have a power LAB ? if not remove PR103 & test which side( Dc jack or +B) is short to GND

No ,i don't have a Power LAB.
Just ordered one,so i will be back as soon it arrives.
You are right ,i have all the others parts, but power, never.

Can you explain to me, how i can test the short to ground as you said,with which way ? ( I am still learning as you figured ).

Clearly, you have a short on the B+ line like @techtiger said.....
I'm opened up to better ideas in case others feel this method is unsafe

Thanks for the reply.

If you want to repair laptops, investing in proper tools is a must. There can be no alternative to lab psu. This battery method will work but its not viable for regular repair job.

You are correct ,Sir!