Chosen Solution
My wife’s iPhone 11 got slightly sweaty which ruined the screen. To be specific, there were several lines appearing and worsening and disappearing. There was also a dark spot on the old screen. I was hoping that replacing the screen would fix both problems. Fortunately the lines were fixed and at first the dark spot was gone, but after about a minute the dark spot appeared again. How can I fix this?
A pic of the screen would be handy to see how big the dark spot is. I haven’t worked on many of the 11’s but if they have the same backlight circuit as the XR it could be your problem. There is most likely two backlight circuits on your phone if one becomes faulty the other one cannot handle the load and will usually result in a dark patch/shadow on the screen. The backlight circuit consists of filters, coils, diodes, capacitors and the driver if one of these components have become faulty it will need to be repaired by a reputable repairer. If it is under warranty I would take it to an apple store. They will not know how to fix it but may work out a deal for a replacement. I would try the repair shop first as it is most likely only a blown filter.
