Black Glitching Screen and Lack of Support

[TeddyVasileva]

Hello, 

I purchased a laptop from a retailer of HP (HP ProBook 440 G7 Notebook PC (6XJ56AV)). My warranty there expires in 2 months. The last 5 months or so the screen of my laptop randomly decides to glitch and go black. I am unable to turn it back on unless I restart the laptop 2-3 times and sometimes even more. 

I tried to give it back for diagnostic and fix at CNSYS PLC service, their claim is that I have spilled sweet liquid over my laptop long time ago and this is why I am having this problem. I understand it may sound strange but I am absolutely sure I have never spilled anything. They informed me that there is nothing they can do and they will send me the laptop the next day. I waited a week for them to "assemble" after they initially said that it is ready to be sent back to me. The whole thing was very unprofessional.  The day I went to leave my laptop at the same service, a woman was having an argument with people at the reception claiming that their lawyer will soon contact them. My experience there was also unpleasant, as I was told to sign unfilled protocols, because they do not have the time right now and would add the information later on. I  looked up their service online and there were many negative reviews. I do not understand how this can be an official HP service.

I looked for second and third opinion without opening the laptop and the results suggested it must be a faulty hardware.

I would be very grateful if somebody suggests how to check if any part is in fact defective. Once more, I am fully aware how it may sound but I know the laptop has never had anything spilled over. Also they did not provide me pictures of the  "liquid damage" that they claimed the laptop had. 

I also tried to preinstall my software and drivers. Any help/suggestions will be highly appreciated.