Why is my iPhone 11 having a black spot in low brightness

Hi zayie,

It may help us give you a firmer diagnosis if we could see a picture of what your screen is doing, so you might consider adding one to your question.

Adding images to an existing question - iFixit Repair Guide

Frankly, it does sound as though the screen has suffered liquid damage. You can give it some time and perhaps even apply some heat via a hair dryer to see if over time it dries out and recovers; it happens sometimes but other times the damage is permanent.

Really, the only thing you can do at this point if it doesn't recover is to replace the screen. Use iFixit's guide right here.

iPhone 11 Screen Replacement - iFixit Repair Guide

Your phone is a bit of a throwback in that it uses an LCD display rather than the newer OLED that most of the other Apple phones use, but the good part about that is the screens are much cheaper. Here's an example.

Amazon.com: Replacement iPhone 11 Screen 6.1inch Black 3D Touch LCD Display with Frame Assembly Repair Tool for Home or Repair Shop Replacement(Model A2111, A2223, A2221) : Cell Phones & Accessories

There are a couple of cautions you should be aware of if you're planning on replacing the screen yourself. First of all, ever since the iPhone 8, the True Tone function will be disabled if you replace the screen unless you copy a small piece of data called the MtSN from the original screen to the replacement with a device programmer. Last I checked those programmers are running about $85 USD and up, so you'd have to decide for yourself if the cost is worth it, especially if you're only going to use it once.

Second, starting with the iPhone 11, Apple has continued with their anti-repair tactics by pairing the screen to the logic board. Fortunately the functionality of the screen seems to be unaffected, but for a couple of weeks you'll get a pop-up notice to the effect that your screen may not be genuine - even if it is a genuine Apple screen. After that the warning will go away but you'll be left with a permanent badge appearing on your settings icon and that same warning appearing under the display settings.

There are only two ways to avoid that warning; first you can remove the Touch Module IC from the original screen and solder it onto the replacement screen. This is a very difficult operation and requires specialized skills and equipment such that ultimately it's really not worth the effort. Of course, the other way is to pay Apple for a screen replacement since only they can re-pair the new screen to your logic board and eliminate the warning.

That being said, good luck with your repair; let us know what you decide to do and how it turns out!