Galaxy S4 Capacitive/Touch Buttons not working after LCD/digitizer assembly replacement

[Matthias Lane]

Hello, I'm having an issue that I hope can be resolved without returning parts, if possible. I have an S4 that had been dropped on it's top left corner and shattered the glass. After waiting forever for it to get in, I swapped out the whole LCD/digitizer assembly, moving over the mainboard, all it's bits n pieces, the wifi antennae, and the lower board with it's touch ribbon that runs along the power button side and connects to the digitizer's cable. Upon first boot, the display, touch, hard buttons, speakers, cameras, light sensor, notification light, wifi all work perfectly fine. The only things that don't work are the capacitive 'back' and 'menu' buttons.

I've tried reseating everything I can think of, making sure there's a connection between the touch cable and it's piggyback digitizer cable, reboot, settings>my device>display>more settings>touch light duration and playing with that before reboot and after, and am about to try factory reset, but 1. It's a coworker's phone and i'm not really wanting to reset it after all this time, and 2. I have a feeling a reset would not remedy this.

Does anyone have any thoughts on what it could be and/or any reasonable suggestions, besides separating the screen? Last time I tried to remove a perfectly good SGS4 glass (after many other successful glass repairs), it shattered almost instantly, and this phone repair has been nothing but disappointments so far.

Thank you.

 

[Spirk]

I'm hoping you found a solution since posting this. I replaced the digitizer/LCD assembly today and the screen does not recognize touches. The power and home buttons work just fine. Did you figure out what was wrong or did you get new parts?

 

[JP Illescas]

Same Problem! any ideas of what can we do???