Question Laptop screen & external monitor both have a black screen ?

[bawse.hustler]

Laptop model: ASUS FX502VM:

• Intel® Core™ i5-7300HQ processor
• NVIDIA® GeForce® GTX 1060 3 GB
• 128 GB SSD & 1000 GB lagring
• 16 GB DDR4 RAM-minne

Problems:

Well when I power on the laptop the screen is just black but keyboard lights up with backlit, and the laptops boots up into windows fresh install since i can hear the Auto voice speaking about which install i wanna do and so on, at this point the screen is still black.

But if i plug in external monitor its also black it dont work to connect either. I have opened the laptop up unplug battery and LCD screen cable and put back in again and tested starting same problem black screen.

After that i removed the lcd screen from the laptop and took out the 30pin cable, and then plugged back in, at this point i tested starting again this time the screen came up so i know the LCD screen is not broken, the asus boot logo shows up i press to enter bios, and i can stay in bios for over 10 min screen stays on no problems, i then exit bios and laptop restart same problem screen goes black and at this point i gotta plug out battery and testing using AC only having battery plugged out nothing matters screen stays black.

It just works magically sometimes perhaps 2% of time each time i start pc up, anyway i have tested New ssd with working windows and new Ram sticks it still makes no difference.
This might be a faulty gpu i dont know for sure buying new motherboard is expensive but its worth it since i got it cheap so i dont lose anything from doing it unless its not the motherboard ;(

Anybody with some experiance that could help me i dont really mind if the pc dies i kinda use it to learn stuff i have a multimeter but i have no experiance regarding volt and stuff i checked some youtube videos thats about it.

I have added video to show that it starts in bios, not always tho just works very small % of times.
https://streamable.com/neqwz7

 

[Lutfij]

You could try and disassemble the laptop, disconnecting the battery, removing the sticks of ram, press and hold down the power button for 30secs. You can then use an eraser on the golden contacts on your rams, wipe clean then reseat on the laptop. Try powering up without the battery(using only the power brick).

If that works, you have a grounding issue.

 

[bawse.hustler]

You could try and disassemble the laptop, disconnecting the battery, removing the sticks of ram, press and hold down the power button for 30secs. You can then use an eraser on the golden contacts on your rams, wipe clean then reseat on the laptop. Try powering up without the battery(using only the power brick).

If that works, you have a grounding issue.

You mean clean the ram with a rubber on the golden bits, should i do it on the motherboard ram connectors aswell?

 

[Lutfij]

should i do it on the motherboard ram connectors aswell?
You might want to inspect the connectors on the motherboard's ram slots and you'll see it's impossible, unless you're looking for an excuse to ruin the board. Simple answer to your question is no.

 

[bawse.hustler]

You could try and disassemble the laptop, disconnecting the battery, removing the sticks of ram, press and hold down the power button for 30secs. You can then use an eraser on the golden contacts on your rams, wipe clean then reseat on the laptop. Try powering up without the battery(using only the power brick).

If that works, you have a grounding issue.

I just tested the ram and no luck. Also i have tested another ram stick that is new and 100% working and same problem. I also tested starting laptop without any harddrive or ssd, but same no picture black screen.

 

[bawse.hustler]

should i do it on the motherboard ram connectors aswell?
You might want to inspect the connectors on the motherboard's ram slots and you'll see it's impossible, unless you're looking for an excuse to ruin the board. Simple answer to your question is no.

Do you know of any way to check if GPU if faulty using multimeter? Its just weird that the screen can work sometimes but mostly not.