Thank you all for your answers, people! I'm currently writing these, while in the office.

I took the keyboard to my technician's store (not where I had bought it from, I had bought it from my hometown), he plugged it to his PC and confirmed to me that it got busted. As honglath describes in post No 5, a power surge must have happened either as my PC was closing down (after the Win 10 upgrade), or while I opened it, when I returned, and this must have short-circuited the keyboard (and nothing else). He described to me that circuits connect different rows of keys inside the keyboard, and the one connecting the aforementioned buttons, is the one that got busted. It's the things that just happen! He ruled out the possibility to be the Win10 upgrade's fault, or any other software related.

The keyboard was very clean and very new, I bought it in August!

However, I have yet to get a new one to end the story, I'll get a cheap one around Christmas and then it will be conclusively determined if it's the Keyboard's fault. I think this is the case though.

Sometimes it just happens, that's what we have warranty for :)

If you say you bought it in August (from inside the EU), its well within the mandatory six months timeframe and you can bring it back to the store. They have provide you with a equal one / refund.
After that period they send it in for manufacturer warranty.

So no Unicomp Model M?

Hahaha! Wow! Very good models, now that I've searched for them, and they seem robust! However, I don't see them in any store in my country, probably not here yet! (Not that I would buy them, that is!)

Btw thanks for the advice, rtcvb32! I didn't know about these combinations. Very useful, until I get my new keyboard!

They're the continuing bloodline of the original IBM Model M; the legendary successor of the Model F, which itself was begat from the IBM Selectric typewriter. Their keyfeel is unlike any other keyboard, and incredibly comfortable, because they were made to be typed on; their mechanism is brilliantly simple.

Imagine if Olivetti had made a lineage that went beyond incredibly stylish typewriters, basically.

Mechanical keyboards have so many selections these days, you'll need a flowchart, several switch demos, and using different models to see what switch is right for you.

https://info.ai03.com/books/general-info/page/switch-choice-flowchart

I think most people can't go wrong with brown equivalent switches as their first and then narrowing their selection from there - MX browns, Gatreons, Gatreon Optical, Kailh, Outemu.

Maybe reds if you only do almost all gaming or blues if you only do almost all typing.

That's why I only use el cheapo Logitech keyboards. If anything happens to them they're easy to replace. My current one has been going strong for 6+ years. ;)

That flowchart is nice, but I think a swearing Dutchman is better: Seeing as he's reviewed over 500 boards.

^ That's very fair. Absolutely should consult multiple sources to get a wider breadth of review. The flowchart above was made by a keyboard product designer based in Rhode Island, US.

I think when you look at keystrokes and lifespans, a mechanical keyboard could be cheaper than having to replace plastic membrane keyboards every 5 years?

Assuming your most pressed keys were 50k keypresses/mo, 50M keystokes lifespan is equivalent to 1 mechanical keyboard every 83 years and this is with cheap Outemu switches. e-waste is also something important to me that I want to reduce, personally.

A good mechanical keyboard will have a USB-C port one can simply unplug before leaving their house if they fear another power surge.

When said cheapo keyboard costs less than $15 and totally fulfills my needs I very much doubt it. Also, can't stand clackity-clack.

One reference by HP is membrane keyboards having 5 million keystrokes lifespan - www.hp.com/us-en/shop/tech-takes/mechanical-vs-membrane-keyboard-for-gaming

If you're spending $15/keyboard, to equate to my $40 USD Outemu keyboard, the BEP would be 2.67 membrane keyboards by cost. If each membrane keyboard lasted me 8.33 years using the 50k keystroke/mo usage, then it'd be more advantageous for me to use a mechanical keyboard because I can get another 61 years out of it by lifespan and don't have to spend the extra time researching and buying more keyboards every single time each membrane keyboard broke down. We also disregard other feature benefits like RGB lighting, volume knob, etc.

Not only that, not all mechanical keyboards are clicky. The red switches are pretty quiet and also are one of the switches I recommend to start with.

If you're already paying $15 USD/membrane keyboard and mechanical keyboards like this are as low as $35 USD and you're not using one, you're doing yourself a disservice IMO - www.amazon.com/GAMEPOWER-Rainbow-Mechanical-Keyboard-Ghosting/dp/B0BWYZ4FN3/

These lifespan figures you're looking at completely ignore oxidization. Mechanical switches do start to oxidize and can go bad in a few years no matter how much or little you use them.

I have two keyboards with kailh box white, both about 5 years old, both have bad switches. And I have one with MX browns that developed the same symptoms, though perhaps it lasted a bit longer than the kailh whites.

By comparison, I've never broken a membrane keyboard like that.. not that it doesn't happen, but these things can seriously last long.

If you want longevity from a mechanical keyboard, it's best to go for a model where the switches can be removed. Then you can either disassemble them and use contact cleaner, or just plop in new switches to replace the failing ones. And ideally pick some popular switches for which replacements are going to be findable long in the future.

This is a good point. Can this issue be heavily mitigated if you have a dehumidifier and/or place desiccants on your keyboard if you live in a humid environment? For storage, definitely should keep it in a sealed container like its box with a desiccant to preserve its condition. Fantastic suggestion!! Luckily my board is swappable and not soldered. I was quite surprised at the $40 USD price point.

Heh, funny story. In 2005 when i was in the army in Korea, i was the tech guy. So after one platoon went on a training mission, came back and the laptop wasn't working. When finding out it was humid in the shelter/truck, i suggested putting the keyboard up on it's side to self-open and just blow a fan on it, preferably with opening the back and whatnot so it could breath and check back in a day or two. Computer was running pretty much perfectly after that.

That reminds me, of how tape formats never really caught on in Asia since they were so much more vulnerable to the humid/tropical conditions compared to optical media; which is why LD and MD were huge there.