bed leveling does not seem possible

I just had the Taz4 delivered and it’s assembled. It looks pretty nice and I have installed the pronterface software. I’m trying to level the bed and the problem I’m looking at is that the two corners on the +X side are about 3-5 millimeters higher than the two on the -X side. If I try to raise the bed on the +X side the screws pop out so there’s no way to raise the bed up on that side. I thought about lowering the +X side and then lowering the printer head but the Z axis seems to be as low as it goes. I’ve tried to lower the Z axis with pronterface and also with the control board but it’s at 0.000 and won’t go lower.

Has anyone run into this problem or have an idea of what may be the issue here?

Thanks.

Your Z axis may not be level in relation to the the rest of the printer. Use this video as a guide: https://www.youtube.com/watch?v=EdB8jbXFfns Remember to measure against the aluminum plate, not the glass bed. If either the left or right-hand side of the printer is higher than the other, with the printer off, turn one of the Z axis stepper motors (while holding the other still) to raise/lower that side until both sides are level. Then re-level the glass bed.