Galaxy SII : New LCD assembly ok while charging; bad on battery

[sgs46]

Installed a new LCD assembly to repair broken on 989 S2. Worked fine before replacement. Phone works fine only if it is on the charger (wall or PC). But on battery, touches anywhere on the primary screen activate only apps at the top of the screen or above the touch point. Home row touches work; screen swipes left to right work. Main screen buttons unresponsive if there are no apps above them. Display is reading 70 to 96% of battery usage which can't be normal. E-Bay LCD vendor isn't cooperating; ridiculous return policy. Be happy to name the vendor if they can't make it right. But I hate to invest for another screen if there's a problem the screen won't fix. ANY ideas would be welcomed. Thanks.