i have gone to the service center to repair it under warranty. the person said that the screen was replaced and the warranty will run out on the original warranty date which is in a month's time.
i won't be surprised if the screen spoils again in a year and by that time the warranty is over. this has been what has been happening to the other zenfone 3 zoom users in the forum.
it's just a poor quality product, most likely using lousy parts to maximize profits. it's my last and final Asus product and i advise everyone including my friend and relatives not to buy it.