Hello. If there are people who are still experiencing the issue, here's my fix.
I had a similar issue: the buttons "4, 5, r, t, f, g, v and b" refused to be used on an ASUS F550J laptop.
CAUTION: In order to not break your computer, ask a friend who has skills in the hardware area or ask for technical support.
EXPLANATION to the fix: The main problem is that the cable, which transfers data from keys to the processor, is touching a hot steel/iron/etc. This causes data loss and the keys permanently stay unusable or at least barely usable.
STEPS to fix:
1. Make sure you know what you're doing.
2. Turn off the laptop.
3. Turn the laptop upside-down.
4. Unscrew every bolt you find.
5. There might be a couple screws under the battery. If so, carefully remove it and unscrew them as well.
6. This steps requires patience: Split the keyboard part from the rest of the laptop but know that there are going to be cables connected underneath. Slowly separate the two parts. Check how on YouTube. It's easy but make sure you have everything unscrewed. Don't unclip any cables, you won't need it. (If you're having trouble later on, you could unclip some but make sure you're very careful, because each has a clip, you need to click.)
7. This is the main step: Make sure you fold the most wide cable, so it doesn't touch any metal. Be careful with the folding, it's delicate. (You might want to straighten the folded area, which was touching the metal. This way, it refreshes.)
8. After you've folded the wide cable without it touching any metal, put the keyboard part back onto the other one. Make sure the wide cable is how you've put it (not touching metal) and is staying that way after the close.
9. Flip the laptop again, whilst making sure you have the cable as you want it.
10. Screw all bolts.
11. You're done. Now check if you've found your fix.