MSI Raider GE66 Short/ no power - weird issues please help

[bigbadbios]

Hi, I have a MSI Raider GE66 i7-10750h, Rtx2070 Super
It will not turn on.
Found IC TI 1225C getting hot on back of MB.
Replaced said IC. Plugged laptop in and heard a pop/smell burned smell. Inspected and I see NOTHING physically burned or damaged including the IC. Now on the power supply i have about .5 volts compared to 20v before.
I am lost at what to do now, your input is greatly appreciated. I spent a fair bit on this one in hopes it's fixable.
Thanks for your time.

[mon2]

Re: MSI Raider GE66 Short/ no power - weird issues please help

Link or post the schematic in the schematic forum, if available.

Start with the power adapter - disconnect it from the logic board. Measure the voltage to ground of this power adapter. Do you have ~19 volts on this adapter?

If yes, continue.

Often, as per the detailed article above by @Piernov, the power adapter connector on the logic board will follow with 2*DCin mosfets. These mosfets are controlled by a local charger IC.

Locate these parts on your logic board and share the topside markings of the mosfets and the charger IC.

Very likely, the fault is in this area and often, with the 2nd DCin mosfet.

Once you find the mosfets = 8 pin package (each). Measure the voltage to ground of each mosfet pin.

Pins 1-2-3 will be bonded together = SOURCE pin.
Pin 4 is the GATE pin and used to enable / disable this mosfet.
Pins 5-6-7-8 will be bonded together = GATE pin.

Mosfet is like a solid-state relay. If the mosfet is N-channel, then the GATE pin must be HIGHER than the voltage being passed between the source / drain pins.

For N-channel, often the gate voltage should be ~25 volts since the adapter voltage is ~19 volts. The charger IC will likely be the BQ series from Texas Instruments and it uses the REGN pin voltage of ~6 volts to BOOST the ACDRV pin to drive the 2*DCin mosfets.

That is, gate voltage = REGN voltage + adapter voltage = 6 volts + 19 volts = 25 volts.

Start with the above review to check on the voltage of each DCin mosfet.

[bigbadbios]

Re: MSI Raider GE66 Short/ no power - weird issues please help

Link or post the schematic in the schematic forum, if available.

Start with the power adapter - disconnect it from the logic board. Measure the voltage to ground of this power adapter. Do you have ~19 volts on this adapter?

If yes, continue.

Often, as per the detailed article above by @Piernov, the power adapter connector on the logic board will follow with 2*DCin mosfets. These mosfets are controlled by a local charger IC.

Locate these parts on your logic board and share the topside markings of the mosfets and the charger IC.

Very likely, the fault is in this area and often, with the 2nd DCin mosfet.

Once you find the mosfets = 8 pin package (each). Measure the voltage to ground of each mosfet pin.

Pins 1-2-3 will be bonded together = SOURCE pin.
Pin 4 is the GATE pin and used to enable / disable this mosfet.
Pins 5-6-7-8 will be bonded together = GATE pin.

Mosfet is like a solid-state relay. If the mosfet is N-channel, then the GATE pin must be HIGHER than the voltage being passed between the source / drain pins.

For N-channel, often the gate voltage should be ~25 volts since the adapter voltage is ~19 volts. The charger IC will likely be the BQ series from Texas Instruments and it uses the REGN pin voltage of ~6 volts to BOOST the ACDRV pin to drive the 2*DCin mosfets.

That is, gate voltage = REGN voltage + adapter voltage = 6 volts + 19 volts = 25 volts.

Start with the above review to check on the voltage of each DCin mosfet.

So I found a mosfet by the battery connector that is shorted I believe, when removed it restores 20v to the board. I am assuming that one of the two big power supplies next to it may be to blame? A little stuck right now.

[Stevedb]

Re: MSI Raider GE66 Short/ no power - weird issues please help

I would suggest make hd picture front and back with all voltages on the coils also resistance to ground with no power to the board.

[mcplslg123]

Re: MSI Raider GE66 Short/ no power - weird issues please help

1225C is your 3V/5V pwm IC. Since it was getting hot, its worth to check resistance to GND on pin3/13 for 3Vldo and 5V ldo respectively. Resistance should be measured without any power source connected.