Asus FX507MP P3V3AL 484 ohm, is normal?

[Dcortest]

Hello,

I'm trying to repair an Asus FX507MP that is nor turning on. It has several faulty components on 5v and 3v3 rail, but now after desoldering several power switch from P5V0AL I have 1,6kohm (waiting for the replacements to resolder the new ones).
But on rail P3V3AL and VRB_VDD3 after desoldering 4 drmos from the GPU i'm having 484ohms could it be a normal value for this rail? injecting 1v only has 0.005A current consuming.
I opened the jumpers from the 3V-5V converter to isolate the load section to diagnose (also opened the P3V3A bridge)

[Dcortest]

Now I fixed it having 1.5Kohms on both power rails (3V and 5V) but the laptop still doesn't boot. Now I have all voltages (main power rail, P3V3LDO,P3V3AL, P3V3A, P5V0AL, P1V8A)
I have RSMRST and DSW_PWROK when pressing power button but not SLP_S3_3R to start P3V3S or PLT_RST
Changed the BIOS firmware with a new one given on this forum wihtout success
I'm a bit lost how to check or if I have a faulty PCH and it's game over

I uploaded the boardview if someone could help me to check something else.... Link to boardview -> https://www.badcaps.net/forum/troubl...%CC%87ew-needs

[Dcortest]

Another question
DSW_PWROK and RSMRST are connected to a drain from from two mosfets, the gate is connected to a 100K resistor that recibes P3V3LDO voltage, I have 3,3V on LDO side from the resistor but on the other side of the resistor I have 0V, but when I press the power button I can see 3,3V on both drain pins for each signal... is this a normal behaviour? or there is something wrong with that gate voltage and is not sending the signal to pch??

[Sephir0th]

Even 1.5KOhms are barely on the border of calling it "good". More likely not.

In such cases it is usually essential to have a full history at hand. About what happened and what you did so far.

This means in particular how you "fixed" the 3V3AL from 500 Ohms to 1.5KOhms, although is is obviously not, for example.

And everything else which may or may not be important.

Also depending on what exactly you have removed from the board (which you also did not share in particular) it might by essential to restore these first too.

Instead you removed the DrMOS for the GPU which have nothibg to do with the situation ln the 3V supply (feel free to enlight us).

But yes, basically it looks like a fried PCH, which can or can not be definitely proven with a detailed diagnose, without replacing the PCH itself.

[Dcortest]

It is an equipment that came with the EC short and several components of the 3v and 5v line had to be changed, including the GPU mosfet that are powered by the 3V3A line. The unit does a first data train in bios but stays high all the time.
The EC seems to be sending signals, but from the PCH I have no PLT_RST, SLP_S3.
The pch is inside the CPU so changing it is not feasible, maybe a reballing?
There are no shorts on the board

[mcplslg123]

Are you sure GPU Drmos powered by 3V3A rail? Never heard that. Check again.

A simultaneous short on 3V and 5V line is an indicator of massive damage and SOC rarely survives that. Btw, whats the resistance to GND on 1.8V/1.05v rail?

As far as Resistance to GND on any rail(eg 3V3A) is concerned, it differs from platform to platform. I just repaired a ASUS X505M(Ryzen) with resistance to GND of 484 ohms on 3V3A rail and its working.

So no one can say for sure whether the resistance to GND is correct or not unless someone has the same mb and noted the resistance to GND.

[Dcortest]

Yes on these dr mos a 3v3 arribes from P3V3AL but it's called VRB_VDD3 you can see pin 34 and 27 but also pin 8 is connected to that 3v line
Monday I'll give you the meassures from 1v8 and 1v05 line resistance to gnd (both lines are working but I don't have the resistance reading right now) but now P3V3AL has 1,6Kohms and P5V0AL has 1,5Kohms
Power button has voltage, EC has voltage, BIOS has vontage a few seconds from P3V3A but goes down and doesn't go up again till power button is not pressed. I can see with oscilloscope a first data pulse on Bios (from each pin 1, 2, 5 and 6) when connecting the power supply and stay high, then P3V3A goes down waiting to power button press, but when I press the button I don't see any data traffic.
RSMRST = 3,2V
DW_PWRON= 3,2V
Both signals goes high when pressing the power button.
Maybe another test it's to write the asus oficial firmare... maybe my firmware version was not good (btw was clean by a member of this forum)