Laptop was dead, no respond to charger..I tear the laptop a part and start to work with one stick of ram..i did get power, but fans at max...so i reprogrammed bios, and yes, i have picture, sound...everything is fine...BUT...
It only works with one specific ram stick in specific slot. I have two same samsung 8 gb ddr4 ram, that work on other laptops but not on this. So in short:
1. If i put a one peace of ram stick in specific slot the laptop works, i can get to windows and play the whole day.
2. If i put that exact ram in any other slot it will not work, i can see backlit keyboard...but no bios, no picture
3. If i put two other working ddr4 ram sticks in any slot it will not work, same as 2

I dont get it? Going crazy..

Looks like soft problem, try another bios dump with clean ME or download from asus support

I tried three bios dumps but same thing...

Update....i was able to borrow from a friend one hynix and one more samsung ram stick...and they work, in that same slot, but not in any other...also, i forget to mention that i use hdmi cable on external screen to check if i have bios displayed, because the original lcd-screen and lcd cable were ruined behind repair....so now i am thinking maybe hdmi is working only( display bios picture) when one memory modul inserted? I checked the last pin on lcd connector on motherboard while two memory moduls inserted, and i have 3.2 v. ?!
In short, maybe hdmi will not post on external monitor bios if two sticks of ram inserted? Or? Any new ideas?

Try to start pushing on each separate cpu corners whithout cooler with 2 memory planks inserted or check soldering integrity with tester:

You mean i finger push cpu towards board while turning on? you suspect bad cpu solder/solder break on motherboad?

Yes, because, as i understand, it turned on after disassembly when motherboard could be deformed and cracked soldering joined

unfortunatelly, that didnt help...i didnt have much time to inspect it in detail but...i found some shorts to the ground on two memory moduls (maybe there is more but didnt have time to check). because there is no boardview i can only assume that it is on m_b_dimm0_sa1 net and similar... i included pictures where i found short, its on the first pins of module:

1st pin must be Vss - ground

check all coil to fid short point

sorry i was reading it wrong, its the last pin 260, SA1 pin according to the pinout

SA1 is usually connected to ground through 10kOhm resistor. Compare resistance of 260 pin to gnd of slot that works and find the element connected to 260`s of bad mem slots pin if resistance will differ.