SOLVED Blind spot

[CreatorCreature 3]

I use an UM2. I am at my wits' end.

It started with warping but only at corners in the left/back quadrant. I adjusted and re-calibrated, I rotated my model to avoid that area and also chose one that had brims around the corners. Additionally, I loosened the spooled PLA to make sure the feeder wouldn't click. I'm not sure my measures were successful but now I observed something even weirder: one spot were underextrusion happens .

The surface is evenly cleaned, it doesn't look or feel different at that spot. How can this happen?

[Nicolinux 288]

Check to see if your glass plate is flat. Take it out, put it on a flat surface and push down all each corner to see if it wobbles.

[CreatorCreature 3]

Holy cow! Occam's razor strikes again. I hadn't thought this is possible but apparently the most obvious is also the real reason: the surface on the side that is being printed on isn't flat.

Now what? Is this covered by warranty?

[Nicolinux 288]

Yes I think so.