Aporte original por: Minho ,
Did you try a known-good screen before doing the micro-soldering? It may be a dumb question but sometimes the problem is not what we think. If you confirmed with another screen that the issue was logic board related, then check the various touch-related voltages to insure they are present and not shorted. If they look good, then consider removing one or the other Touch IC (one at a time), it may have a connection issue with one of the solder balls.