[ iFixit ] Julia Bluff:
Replacing the touchscreen doesn’t fix the problem. The gray bar eventually shows up on the new screen, too. Because, according to repair pros, the problem isn’t the screen at all. It’s the two touchscreen controller chips, or Touch IC chips, on the logic board inside the phone.
These two chips are: U2402 Meson and Cumulus U2401. Some micro-soldering professional seem to think the U2402 touchscreen controller chips have a manufacturing defect. But most think it’s because the small solder balls that connect the touch IC chips to the logic board start to lose contact with the board. Why? Because it’s easy to. Cured underfill beneath chips help secure solder balls, but there are none for the touch IC chips in the iPhone 6 and the 6 Plus. And there isn’t a strong metal shield over the chips to prevent bending, which is what the iPhone 6 and especially the iPhone 6 Plus do. When the iPhones bend the logic board does too and eventually loosens the IC chip connections to the logic board. When that happens you have an unresponsive touchscreen.
The iPhone 6s and 6s Plus are immune to what’s called Touch Disease, because these touch IC chips were moved off the logic board and into the display assembly.
So how do you fix your Touch Diseased iPhone 6 or 6 Plus? First, if your iPhone is still within the warranty period, take it to Apple and do your best to upgrade to the 6s or 6s Plus. If you’re out of warranty, find an independent repair shop that can do board-level micro-soldering and has experience fixing Touch Disease. Make sure the two touch IC chips are replaced with new ones. Some shops are covering the chips with a strong metal shield to prevent bending. Here are the repair shops that were mentioned in the iFixit article:
Apple’s design schedule for the iPhone has been relatively simple: the non-‘s’ versions have new designs and the ‘s’ versions enhance the internals. Brand new designs are new and no matter how hard Apple works at it Apple can’t get all the kinks out. So my recommendation is to go with ‘s’ versions of iPhones if you can; they tend to have less problems.
But that might require you to wait a really long time for a new iPhone because rumor has it the new iPhone scheduled to be introduced on September 7 will be called iPhone 7 and the next one will be iPhone 8. No iPhone 7s this time around. I don’t know if I’ll be able to, but if I want to minimize the chances of having hardware problems like Touch Disease, I’ll have to stick with my iPhone 6s until iPhone 8s comes out in 2018.
[ MacRumors ] Apple will now fix your iPhone 6 Plus with an unresponsive touchscreen, for $149. And it’s your fault — for dropping your iPhone 6 Plus multiple times on a hard surface and putting stress on it. From what I can tell, Apple doesn’t seem to be owning up to the fact that the internal design of the iPhone 6 Plus looks like they were developed by first-year interns and prone to causing defects, compared to the highly professional and sturdy design of iPhone 5s.
My theory is: Apple put too much emphasis on making the device thinner and lighter. Because of that focus all other considerations were secondary.