Bed warped suddenly?

[maxed280]

OK update,

Glass plate installed, bed prepared and filament sticking well enough.

However seems like there is a hump smack bang in the center of the build plate. if i level on all four corners the put the nozzle in the center it touches the glass. this means i have to back off the four corners that causes its own problems.

so what could it be now? cant be the glass warped also. so now its got me thinking something is bent or loose?

any ideas where to start?

cheers

[EagleSeven]

Did you try putting a known Straight-edge, like a metal Ruler, on bed ?
To try to see if it is really warped.

I'm thinking the Tubes, that extruder assembly moves on, may be Bent down in center ?
But I don't see how they could get bent with normal use.
The tubes in our printer have not bent and I've put a Lot of pressure on them during extruder Clean-outs.