If old and new screen are showing the exact same issue, odds are the drop that cracked the screen caused damage somewhere else on the board or someone trying to fix it caused pry or other damage.
I'd start by examining the whole board using 20x or more magnification for traces of damage mechanical (I mean things seem broken damaged, missing, or part removed from the board) and possibly liquid damage.
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EDIT: had this same exact issue and have seen it all over the place with other repair businesses. This issue is due to the touch circuit being damaged, primarily the touch connector on the board and the touch IC. Reflowing/reballing those 2 fixed it in ALL the cases encountered so far. Not to say that there could be other causes. I did it myself in two different cases and succeeded in getting rid of the issue.
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EDIT: this issue is ever more recurring. We are encountering a lot of touch issues: intermittent or permanent loss of touch, accompanied with flickering on the top of the screen, and sometimes other visual artifacts on the screen.
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To fix this issue permanently, we are replacing one or both the touch controllers AKA touch ICs. This often occurs after a drop, a bent in the housing, sometimes after a screen crack and sometimes without any evidence of drop on the phone housing.
If old and new screen are showing the exact same issue, odds are the drop that cracked the screen caused damage somewhere else on the board or someone trying to fix it caused pry or other damage.
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I'd start by examining the whole board using 20x or more magnification for traces of damage mechanical (I mean things seem broken damaged, missing, or part removed from the board) and possibly liquid damage.
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I'd start by examining the whole board using 20x or more magnification for traces of damage mechanical (I mean things seem broken damaged, missing, or part removed from the board) and possibly liquid damage.
-
EDIT: had this same exact issue and have seen it all over the place with other repair businesses. This issue is due to the touch circuit being damaged, primarily the touch connector on the board and the touch IC. Reflowing/reballing those 2 fixed it in ALL the cases encountered so far. Not to say that there could be other causes.
+
EDIT: had this same exact issue and have seen it all over the place with other repair businesses. This issue is due to the touch circuit being damaged, primarily the touch connector on the board and the touch IC. Reflowing/reballing those 2 fixed it in ALL the cases encountered so far. Not to say that there could be other causes. I did it myself in two different cases and succeeded in getting rid of the issue.
If old and new screen are showing the exact same issue, odds are the drop that cracked the screen caused damage somewhere else on the board or someone trying to fix it caused pry or other damage.
-
I'd start by examining the whole board using 20x or more magnification for traces of damage mechanical (I mean things seem broken damaged, missing, or part removed from the board) and possibly liquid damage.
+
I'd start by examining the whole board using 20x or more magnification for traces of damage mechanical (I mean things seem broken damaged, missing, or part removed from the board) and possibly liquid damage.
+
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EDIT: had this same exact issue and have seen it all over the place with other repair businesses. This issue is due to the touch circuit being damaged, primarily the touch connector on the board and the touch IC. Reflowing/reballing those 2 fixed it in ALL the cases encountered so far. Not to say that there could be other causes.
If old and new screen are showing the exact same issue, odds are the drop that cracked the screen caused damage somewhere else on the board or someone trying to fix it caused pry or other damage.
I'd start by examining the whole board using 20x or more magnification for traces of damage mechanical (I mean things seem broken damaged, missing, or part removed from the board) and possibly liquid damage.