The 0 became unresponsive first, then the S key stopped working next a few minutes later.
I was in middle of a game and tried to use the hotkey "0" above the O and P keys. I had to resort to using the 0 on the number pad because it still worked. My first thought immediately was a game bug. Then the "S" stopped working so I couldn't reverse my character.
I did a restart. This did nothing. Rebooted to safe mode. Still not working. Had to use OSK and then resorted to a USB keyboard to get here to try to find a fix. Everything else works normally. What is my next step before using the warranty? Did a complete scan and safe mode does not fix the problems, so it is definitely not a virus or software issue.
I would also like to state I am experienced with computer repairs, but I do not want to remove the keyboard to check cables yet. I am afraid this could void my warranty. If I can removed all back panel screws, then remove the C on top. I should be able to just pop off the keyboard and check for any internal hardware problems. But, I do not want to void the warranty. This toy was not cheap.
To the best of my knowledge, as long as you don't break any of the WARRANTY VOID IF REMOVED OR DAMAGED stickers, you're allowed to open it up. (that said, I'd still see if you could get in a chat with Asus support and double check that that's allowed.) That said, this sounds like a bad keyboard; I've had lots of laptop keys die on me before, but never four at once. Make sure that those are the only keys affected, and then remove the key caps, check to see if anything has gotten under the key membranes or anything, or if any have been damaged.
With the way keyboards are designed, often times many keys will be on the same circuit (if you hold both Shifts, you probably can't type any of the keys between them because of this), and it's possible that all those keys are on the same circuit and that circuit is damaged, in which case you probably need a replacement for the top panel including the keyboard... which, at $99 last I checked, is pricey. (unless you can get just the keyboard alone? Amazon appears to have just that for 70 bucks... not much better.) You're probably gonna have to go for the warranty repair if there's no easily visible problem you could fix, unfortunately.