Dell Alienware 17 R3 - LA-C912P Motherboard repair - 7 Beeps

[tech_guru]

Hello.
I am having a disappointing motherboard repair with this laptop and I need your help.
This came in with water damage, doing absolutely nothing, and had almost all standby voltages shorted. I have already replaced all those shorted components:
-UE5 SIO KB9022QD - Programmed spare one, when replaced, 3.3v short got out
-PQ102 MDV1525URH
-U17 AOZ1331
-UE1 C8051F383-GQ
-PU800 SY8032ABC
-UI2 SY6288D20AAC
-PU508 RT6220AHGQUF 7P=
-PU100 TPS51225CRUKR
-PU300 TPS51212DSCR

Now, I get all the standby voltages, it turns on BUT with no lights and image. Fans spin for 5 sec then off, then again on and off until after 30 seconds where it beeps 7 times. Google shows 7 beeps is a CPU issue (FYI, CPU gets hot)
The weird thing I see is with PL509 (+VCCIOP) which gives 0v when I press the power button and has 0ohm resistance.
When PJP505 gets open-disengaged, PL509 has 0.9v.

Can you please check the schematics and boardview, if you have them (I don't know if I can attach them here because schematics has watermark), and see if that means that the CPU chip is dead for sure?
I don't know how to continue, I cannot fully understand the power sequence from this schematics. If the CPU needs replacement it will be a no fix unfortunately.

Any help would be appreciated! Thanks!

[SMDFlea]

Can you please check the schematics and boardview, if you have them (I don't know if I can attach them here because schematics has watermark)

Schematic ---> https://www.badcaps.net/forum/showth...132#post953132
PDF Boardview ---> https://www.badcaps.net/forum/showth...679#post987679
Boardview (*.cad) ---> https://www.badcaps.net/forum/showth...13#post1198813

[mcplslg123]

What is the resistance to GND on cpu side of PJP505? Very very likely cpu is shorted.

[tech_guru]

Unfortunately on the cpu side is 0ohm, measured with digital and analog multimeter. Also, I tried to voltage inject 1v with 5A limit on this coil and it gives out 1v 2.5A. The voltage does not drop. With this injection, CPU does not get hot. Is there any chance it is something else you believe?

[tech_guru]

Let me note that the coil PL509 is 0.19v when PJP505 is connected, when disconnected 0.9-1.0v like I said in the first post, and PL508 +VCCSA is 1.1V.

[mcplslg123]

Since cpu side is 0 ohms,its game over unless you decide to replace the SOC.