Lenovo G50-70 ACLU1/ACLU2 NM-A271 no power on

Hello,
I have a G50-70 with a problem that it doesn't powers on.
On the source pins of PQ302 i have 19V OK, the drain voltage is zero.

I've found a similar thread here lenovo-g50-70-aclu1-aclu2-nm-a271-works-only-with-battery-t42459.html but it's not the same problem as I have the 19V on P2 and VCC of PU301. Also replaced the transistor to no avail, checked old one and it's ok.

I've tried to understand the circuit but it's so convoluted and full of interlocked signals coming from everywhere that I don't understand how it works or why have they setup like that, for example PACIN, ACOFF, BATT_OUT it's not clear what are those signals because they affect the gates of the pass mosfets.
For example if PQ304 turns on, it bypasses the 200K resistor putting the gates to 19V and the mosfets will open (and why did they use a bipolar for that?), but if batt_out is set it connects the 20K resistor in series making a 200/20 divider putting the gates to 1.7V, but if PACIN is high (or ACOFF low) then it puts a 68K on the divider which should make the fets conduce even less (see why am i so confused!).

AFAIK the gates of PQ301 and PQ302 need to be to ground for them to fully conduct!

If i bypass PQ302 with a wire, the notebooks turns on ok (but PQ301 is NOT conducting and only using it's diode so i tested for a couple seconds).

All these tests are done with no battery.
Haven't tested with battery as it's flat (according to customer, the notebook kept working on battery until it died).

Any ideas? I have the full schematics in PDF.

Measure the voltages on all pins of PQ301, PQ304, PQ305, PQ307, PQ990, PQ998.
Measure the voltages on pins 5, 6, 8, 9, 16, 17, 20 of PU301

measures WITHOUT battery:

PQ301:
1~3: 19.8V
4: 20V
5~8: 20.4V

PQ304:
1: 20.4v
2: 19.87v
3: 19.8v

PQ305:
1: 19.8v
2: 0v
3: 0v

PQ307:
1: 0v
2: 3.26v
3: 0v
4: 0v
5: 3.26v
6: 0v

PQ990:
1: 0v
2: 0v
3: -0.006v rapid pulsing (i can see it in the measure bars of the DMM it's not straight DC)
4: 0v
5: 0v
6: 20.4v


PQ998:
1: 0v
2: 0v
3: 0.07v rapid pulsing (i can see it in the measure bars of the DMM it's not straight DC)
4: 3.3v
5: 0.004v
6: 3.26v

PU301:
5: 0.0043v
6: 2.67v
8: 0v
9: 0v
16: 6.04v
17: 5.82v
20: 19.87v

btw, pins 8 and 9 are i2C bus, what's the point of measuring them?.

Also, i'm trying to charge the battery externally with a laptop battery tester to do a test with only battery(to see if it powers on) and it won't charge at all(the charger is not id'ing the battery) i suspect whatever the fault has possibly fried the battery controller board (the battery does output the rated voltage with the enable pin shorted, but i dont know how much juice is left)

check R303 R306 and PQ307

Desoldering PQ304 and measure the voltage on pin 4 of PQ301.
Check PR303 = 200K, PR307 = 68K.

i concur that there's something odd in those gate nodes as like greatonline pointed, with PQ307B conducting the divider should lower the gate voltage.

i've taken the measurements for the resistors (those 0402 packages are a real pain to desolder!) and all resistors are in value
PR303: 200K
PR307: 68K
PR356: 20K

Next desoldered PQ304 and measured the gates of Q301 and Q304 and they are still 20V!. Doublechecked PQ307B pin 3(and also measured on PR307 body) and it's still to ground, 20V on PR307 as well.

next i've checked to see if there is any short(maybe a shorted cap) between the gates and the sources(pins 4 to 1~3) that would explain the persistent 20V but there where no shorts at all

EDIT late afternoon: Good news guys, after some thinking about why there was 20V i checked resistance and between gates and sources there was only 1~KΩ!, that's why the divider was not working.

Removed PQ301 and now i could measure PR303 in circuit(i had to lift it before because it was measuring bad)!, measured PQ301 after that and it's definitely bad (fused bad internally most likely)
Replaced it with another AO4407(and i could still measure the 200K of PR303 as it should be) and now i have the correct 5V in P2-1, the motherboard appears to turn on(power led is on, fan spins for a second and stops)!, ran out of time to connect the display or VGA output and to test if the battery charges/works.

On the coils a voltage is present.
On external monitor works?

The notebook is fully tested an operational now, thread can be closed