Readers are reporting that some iPhone screens are brighter than others at the full brightness setting (toggled by going to the Settings application then tapping Brightness). The screens that are not as bright also exhibit a grid pattern on the background -- not a set of vertical lines on the setting screen, which is normal, but a checkered pattern of horizontal and vertical lines in all applications).
A picture posted at ImageShack displays the problem. The phone on the left is clearly dimmer, the phone on the right significantly brighter.
It appears that there are two distinct revisions of iPhone LCD panels: 5 series and 7 series. You can check which version you have via the following process:
- Put your iPhone in field test mode by accessing the Phone application, tapping Keypad, then entering *3001#12345#* and pressing Call.
- Tap Versions
- Inspect the entry next to LCD Panel ID
Users have reported that iPhones with LCD Panel IDs that begin with 7 exhibit this problem, while those with IDs that begin with 5 do not -- though we've seen reports from users with 7-series screens that do not exhibit the issue.
When checking whether or not your iPhone has this issue, make sure to turn the Auto Brightness setting off in the Brightness section of Settings, then reset your iPhone (Press and hold the Sleep/Wake button and the Home button at the same time for at least ten seconds, until the Apple logo appears.) Ambient light sensitivity may simply be affecting your iPhone's screen brightness.