Green Screens\ Garbled Colors Flowing On Laptop Screen [During Bootup]

It's a 15.6" HD Truelife Display (Intel Graphics) Dell Inspiron 3543 (15 3000 Series) Laptop I bought in 2015. My PC is slowly failing, when I boot up the screen gets filled with strange garbled color patterns & stops when Windows 10 has loaded, but yesterday it continued a few seconds after my desktop appeared, so I'm really worried. I don't want to have to take it to the store to get it fixed ! It doesn't crash but distorted\ blurred lines & circles appear [almost psychedelic] … What could be causing this ? I keep it carefully on a desk.

UPDATE: Helps me to know what I'm dealing with, I did some posting & was told it could be a memory problem\ CPU is failing —this might cost a lot, could you give me an approximate estimate ? :: https://www.bleepingcomputer.com/forums/t/702085/white-screens-garbled-colors-flowing-on-lappy-bootup/?p=4845396 I upgraded my RAM to 8 GB a few years ago (from 4 GB) because this brand new laptop was Dead On Arrival, & was crashing\ freezing non-stop (I live in Sri Lanka. (I have an extended Warranty upto 5 years which expires in September 2020)): http://en.community.dell.com/support-forums/laptop/f/3518/t/19657225 (my previous resolved issue.) Later I gave it to the store & repaired\fixed it for free as part of my warranty, since the upgraded RAM didn't solve the lock-ups issue (maybe a WiFi Card or some problem.) Now I'm dealing with this; at first I thought it was due to a spike in the electric power socket, but then even in Battery Mode I see those colors skewing & stretching all over the screen, so it had to be a hardware\ software glitch. I also found out it could be a bad lcd screen connector cable: https://www.dell.com/community/Inspiron/Laptop-screen-flashes-red-green-blue-black-on-start-up/td-p/6054737

Another forum (BleepingComputer) mentioned MemTest86, I've been told that before, might give it a try. Dell has its own memory diagnostics tool in BIOS, I've run that before. My HardDisk was almost full & I freed some space thanks to a Flash Drive; also there's some really tiny mites coming out of my lappy keyboard so it could be a physically damaged internals defect as well, not ruling that out … But I surmise it will cost 90 USD+ for replacing the CPU !

P.S: Could it also be 'cause I wiped the screen with a wet cloth ?

UPDATE: I removed my attached USB keyboard & mouse, & reinstalled my BIOS driver, so let's see how it goes. I will need to check once it has been turned off for a few hours. The USB keyboard & mouse have been known to cause problems in the past. Also ran Dell Diagnostics via F12 in Boot & all tests passed, there was nothing faulty. Also once the blurriness is over, I can reboot & then there's no more distorted colors in the screen, so it's an ephemeral thing. If it prolongs, I will take it to the store for a free repair (there's 1 year left in the extended warranty.)

P.S: Unplugging the USB keyboard & mouse made no difference, so I plugged them back in ...

Took a few screenshots from a cellphone to show you, it starts working normally after a few seconds of the distortion, but it gets worse everyday. 20190809_163655.jpg: The last one is after it subsides (My taskbar + desktop icons are auto-hidden in my last screenshot.)::

green screens garbled bootup (for a few seconds--gets worse daily--now upto desktop win10-logon)display works normally again after a few seconds-crops up again after turned off for a few hours & turned on again