definitely the bottom section of cheap digitisers not being taped off correctly next to home button. Lie the new and original digitisers next to each other. To test if this is your fault lift the digitiser very slightly away from the screen from home button end (be careful not to lift too far due to the ribbon cables underneath) and try the home button lock button screen fade etc. worked for me. Switch 2 x tape pieces (one square shaped and one rectangular ) and don't forget clear spacer tape under square section. hope this helps
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