Did you went on vacaction or working trip for 3~4 weeks?
Do you know if theres was some electrical storm during that time?
Did you left your PC plugged to the socket wall during that time?
So you tested your monitor and its working on your laptop, using that HDMI cable, correct?
Did you by any chance move the PC around the house or using a car prior to this problem ?
Whats the system specs, brand and model of every component?
1. No I wasn't on a vacation for 3 4 weeks, but I use my pc only for gaming and I don't have much time for that so I game usually 1 weekend in a month or 2.
2. There was indeed thunderstorm during that time but no thunder strike near my home.
3. Yes, my pc was plugged in to the socket wall, although it has a button when turn that off even if I try to turn on my pc from the power button won't have effect unless I turn on that othat button.
4. Yes in my daily basis I use my laptop for work and I use the same monitor and same HDMI cable, it works without any problems.
5. No I didn't it was on the same place the whole time.
6.
Motherboard: BIOSTAR TB250-BTC 6.0
Graphics Card: NVIDIA GeForce GTX 1650
SSD: Verbatim 1TB SATA 3, M.2 2280.
RAM: 1 slot 16GB DDR4
CPU: Intel Core i5 6500T