Answer to: sleep/lock button not working after screen assembly replacementI changed the screen for the ipad mini 4 and didn't realize the bottom ribbon cable was soldered to the connection. I heated it with a heat gun and was able to remove the cable from the connector with a pair of tweezers, but I had to use extreme caution. it took a long time to get it loose. I actually broke the connector on the top getting it loose. Once loose, it used a magnifying glass and pair of tweezers to push the end of the ribbon cable into the connector. holding my breath, I connected the screen to the motherboard and tested it and luckily it worked and the button also functioned normally. I don't think I will be doing any of these replacements as it was extremely time consuming. Best of luck to all!