Nitro 5 AN515-51 - Burned KBC and regulator - LA-911P

[magneh]

Re: Nitro 5 AN515-51 - Burned KBC and regulator - LA-911P

Yes maybe. Are you sure theres no bridged pins on the SIO .Check for corrosion or liquid damage on RB13 and JHS1 pin 2 LID_SW#

No, SIO pins have been triple checked all good.
I could try a different SIO just to be sure, but I dont have any spare

Machine is super clean not a minor sign of corrosion.
Only thing I could see were the 2 burned ICs I replaced
lll doublecheck

[magneh]

Re: Nitro 5 AN515-51 - Burned KBC and regulator - LA-911P

Yes maybe. Are you sure theres no bridged pins on the SIO .Check for corrosion or liquid damage on RB13 and JHS1 pin 2 LID_SW#

Double checked no corrosion or any liquid damage whatsoever.

Only those 2 burned ICs as I referred.

Since the SIO was burned, and that I can hear the clicking sound at the PCH, could this indicate a bad chip?

Power consumption is 2ma - 23ma - 2 ma and cycling
This 23 mA peak matches the clicking sound on the PCH.


I suppose I could try to lift PCH with hot air (not going to be easy) and check if cycling goes away and if+3VLP_EC stabilizes?

If anyone has some suggestions, I will be willing to try.
If not, RIP

Thanks!

[mcplslg123]

Re: Nitro 5 AN515-51 - Burned KBC and regulator - LA-911P

If you try to lift the PCH with hot air, you are surely going to damage the mb with broken tracks on pcb. You need a bga machine for the purpose.

[Sametbey]

Re: Nitro 5 AN515-51 - Burned KBC and regulator - LA-911P

Have you tried dividing JP2 and giving 3v to 3VLP_EC? how many mA it draws. Are there any heated parts? When the PU401 receives a 12 pin ENB signal, it will start to output 3VLP. Not only 3.3v circuitry but other (audio, ethernet, cardreader, PCH) may be problematic.

[magneh]

Re: Nitro 5 AN515-51 - Burned KBC and regulator - LA-911P

If you try to lift the PCH with hot air, you are surely going to damage the mb with broken tracks on pcb. You need a bga machine for the purpose.

Well, with some patience and good preheating , I think its doable.
its not a huge BGA , so I think it could work

But yes, BGA machine is the right away to do it, no doubt.
It would just be an option to check if the +3VEC would be stable without it

[magneh]

Re: Nitro 5 AN515-51 - Burned KBC and regulator - LA-911P

Have you tried dividing JP2 and giving 3v to 3VLP_EC? how many mA it draws. Are there any heated parts? When the PU401 receives a 12 pin ENB signal, it will start to output 3VLP. Not only 3.3v circuitry but other (audio, ethernet, cardreader, PCH) may be problematic.

Yeah, if I open JP2 and inject 3v, I get 10mA , so nothing heating up or any type of short.
With JP2 closed, I get 72ma , so nothing wrong IMO

ethernet 3.3V have been disconnected and still the same.
Maybe I can try to remove audio and card reader IC or anything that delivers the 3.3V

As I hear the PCH clicking, and since SIO was burned, maybe it damaged the PCH ...

[magneh]

Re: Nitro 5 AN515-51 - Burned KBC and regulator - LA-911P

Does anyone know how I can find what IC is this? PU401?

Cant find it by the letters on it...AWV701

I removed the SIO, and 3.3V EC is stable now.

But this IC should output 3VALW and its not... and its also responsible for 3V and 5V rails activated by the SIO
Pin 11 EN is present.

So I think this IC could be the responsible for this, but would need a datasheet to check

Any idea?

[khaahk]

Re: Nitro 5 AN515-51 - Burned KBC and regulator - LA-911P

Datasheet for SY8286B is not available ("A" is but there are differences). But yes it is responsible for 3V, the smps output should start after enable signal on pin 12 is present. (should come from SIO which you have removed).

[magneh]

Re: Nitro 5 AN515-51 - Burned KBC and regulator - LA-911P

Datasheet for SY8286B is not available ("A" is but there are differences). But yes it is responsible for 3V, the smps output should start after enable signal on pin 12 is present. (should come from SIO which you have removed).

Thanks, sad theres no datasheet


I have the PIN 11 enable at ENLDO_3V5V

Should this be enough to get output at pin 14 +3VALWP?

or needs to be enabled at pin12?

Just trying to be sure that I should have +3VALWP present without the SIO or not

[khaahk]

Re: Nitro 5 AN515-51 - Burned KBC and regulator - LA-911P

SIO gives enable signal to pin 12 for +3VALWP to start.

[guardiny]

Re: Nitro 5 AN515-51 - Burned KBC and regulator - LA-911P

I have same problem in mines too... Did you solved ?

[leovalpo]

Re: Nitro 5 AN515-51 - Burned KBC and regulator - LA-911P

La nomenclatura “+3VLP” en un diagrama esquemático se refiere a una fuente de alimentación de 3.3 voltios. El sufijo “LP” indica que la fuente de alimentación es de baja potencia (Low Power).
Mirando el esquema, esta señal es un voltaje que se crea para probar la corriente y (para este caso) alimentar el SIO (EC) y encenderlo.
El problema entonces, es que no se está superando esa prueba, por ende el SIO (EC) no se encenderá.
Es muy posible que el SIO (EC) esté con una falla (bueno, el colega dice que SIO estaba dañado y que se oye un sonido en el PCH, entonces este último también debe haberse dañado. Recordemos que el SIO (EC) es un circuito de protecciópn general de la Placa Lógica, o mejor dicho es el PMU (Unidad de Energía altamente integrada, regulador de voltaje multicanal).

Para finalizar, y para entender mejor, suponiendo que el PCH está OK, si no hay +3VLP, entonces (para este caso) no hay encendido de SIO (EC o KBC como le dicen algunos), y considerando que todo el resto de fuentes o POWER RAIL no están en corto, es muy seguro que solo esté dañado el SIO (EC o PMU).

Por favor, si estoy errado, corríjanme.

Gracias por leerme.

Atte.,

Notebook Centro® CHILE

The nomenclature “+3VLP” on a schematic diagram refers to a 3.3 volt power supply. The “LP” suffix indicates that the power supply is low power.
Looking at the schematic, this signal is a voltage that is created to test the current and (for this case) power the SIO (EC) and turn it on.
The problem then is that this test is not being passed, therefore the SIO (EC) will not turn on.
It is very possible that the SIO (EC) is faulty (well, the colleague says that the SIO was damaged and that there is a sound in the PCH, so the latter must also have been damaged. Let us remember that the SIO (EC) is a general protection circuit of the Logic Board, or rather it is the PMU (highly integrated Power Unit, multi-channel voltage regulator).

Finally, and to better understand, assuming that the PCH is OK, if there is no +3VLP, then (for this case) there is no SIO turning on (EC or KBC as some call it), and considering that all other sources or POWER RAIL are not shorted, it is very likely that only the SIO (EC or PMU) is damaged.

Please, if I am wrong, correct me.

Thanks for reading me.