Lenovo Legion Y530 turns on but no display or external display

[D87]

Hi
Im trying to repair a Lenovo Legion Y530 that turns on but has no display or external display.
ive already tried resetting it and removing ram one at a time to see is there is any change but it did not work.
the laptop just turns on and fans both spin but no screen, nothing.
the schematic and boardview ill try to attach below...any help would be greatly appreciated since im new to board repair but im trying to learn.

With no power , no charger , no battery no Cmos coin ,
With multimetre at diode mode , red probe at GND and with black probe taking all the measurements at All the grey coils i get this

PL601: .440
PL602: .310
PL201: .548
PL1401: .228
PL3102: .004
PL2101: .117
PL1801: .102
PL5802: .001
PL5801: .001
PL5803: .001
PL901: .058
PL3201: .016
PL3004: .002
PL3001: .002
PL3002: .002
PL3003: .002

as for the mosfets, i only have 7 measurements so far but i will try to get the rest of them tomorrow.
the 7 readings i have so far are

PQ601: D-408 S-310 G-738
PQ602: D-310 S-0 G-425
PQ603: D-407 S-439 G-871
PQ604: D-440 S-0 G-425
PQ201: D-1.665 S-1.625 G-1.635
PQ202: D-408 S-1.625 G-1.635
PQ206: D-549 S-0 G-346

[lapfix]

Re: Lenovo Legion Y530 turns on but no display or external display

Good , since there's no short can you take the voltages measurements .

Consumption on dc supply

Ram socket =
pin 255 = VDDSPD
pin 111 = VDD_1
pin 258 = Vtt
pin 257 = VPP_1
pin 254 = SDA
pin 253 = SCL
pin 108 = PCH_DRAMRST

PLT_RST# = UE1 = pin 22

[D87]

Re: Lenovo Legion Y530 turns on but no display or external display

but arent these ones considered a short since the diode reading is this low?
PL3102: .004
PL5802: .001
PL5801: .001
PL5803: .001
PL901: .058
PL3201: .016
PL3004: .002
PL3001: .002
PL3002: .002
PL3003: .002

[mcplslg123]

Re: Lenovo Legion Y530 turns on but no display or external display

You should'mt measure resistance on Diode mode. Instead use resistance mode(200 Ohms ). Newer mb with onboard soc will show very low resistance on cpu/gpu rail. Anything near 002 Ohms is not considered short on 8th gen onwards. On GPU even 0.500 ohms is not short on new age gpu's. So its confusing but with experience and exposure to many boards, you can judge by yourself which one is shorted. Many engineeres do the fatal mistake of taking it as short and start random injection of voltage and thus killing the SOC.

[D87]

Re: Lenovo Legion Y530 turns on but no display or external display

i tried taking the ram measurements after pluging in the power adapter and i messed it up elsewhere on the board.
now i have no power at all
when i plug in the power adapter to the board the PU601 gets extreamly hot and in diode mode on pin 3 i get .001 and also on the capacitor next to it .001
but all the other pins on that PU601 i get good measurements in diode mode.
i removed the capacitor next to it PC603 which also gave diode reading of .001 but problem remains. it still gets extreamly hot (the PU601) and i have no idea what i should/need to do now

[D87]

Re: Lenovo Legion Y530 turns on but no display or external display

should i remove/replace PU601 ?? anyone know or have suggestions?
i attached the information i found on the PU601 below

[foshland]

Re: Lenovo Legion Y530 turns on but no display or external display

Hi, meassure again, in resistance mode, PL1801, it should be arround 80 ohms

[D87]

Re: Lenovo Legion Y530 turns on but no display or external display

i was not sure how to measure in resistance mode ...im used to diode mode so anyway i tried once with black probe on ground and red probe to PL1801
and then the other way around with red probe on ground and black measuring PL1801 i shared the pictures of the measurements below

[D87]

Re: Lenovo Legion Y530 turns on but no display or external display

also i did remove PU 601 but short was still on the pin 3 pad on the motherboard so i removed PC603 to check again but still short remained so i put them back and removed the jumper PJ603 connecting +3VLP to +3VL and now the short is gone from the pin 3 of PU601. (which is +3VLP)
so im not sure where to go from here, i followed +3VL from pin 1 of PJ603 jumper and below you can see 15 nets it shows on the boardview but again i dont know what to do now so any advice and or help would be greatly appreciated