Ender 3 v2 Neo, has *every* problem

Ender Series Creality Ender-3 V2
1

I have an Ender 3 V2 Neo for about 2 years. It started out working fine, and after about 6 months started being fussy. So I went through all the Z offset stuff, cleaning the plate, replacing the nozzle, and it became “workable” but still fussy. It has continued to get worse, and is now completely unusable. When I say it has EVERY problem, that is what I mean. Very inconsistently, that is what has made troubleshooting so hard.
Example: I print a Z-offset test. For about 10 or 15 lines, it prints perfect, then the next 10-15 lines, the offset is clearly way to close, then the next 10-15 lines way to far. And I can print the test again right after, and get totally different results.
If I somehow manage to get the first layer to print (by constantly adjusting the offset) then at some point before the print is done (maybe 3 hours in), the nozzle will hit the piece, and knock of off the plate.
Or, I will get a low temperature warning and the print will stop.
Fairly frequently, the Z will be so far off that the nozzle is 1 or 2 centimeters of the plate.
The first layer is often ruined from filament oozing or stretching and leaving strings everywhere. I also have adhesion problems.

What I have done:
Level the bed manually, Set the Z offset with paper, then auto level.
Run a Z-offset test print.
Auto home and auto level before every print.
Clean the bed with soap and/or alcohol
Replace the build plate.
Replace the nozzle.
Replace the temp probe,
Replace the whole hot end assembly.
New filament.

None of that made any difference at all. The printer is completely unable to complete a print. And like I said, it’s totally inconsistent. The symptoms and problems are different every time I try to print, Even if I don’t change any settings.

I am ready to toss it in the trash and buy a different brand.

2

Hi

Have you checked the Z screw is fully secure and clean.

Not familiar with the v2 Neo, does it have one stepper motor and a belt to the other screw?

Check the gantry height at least 2 different levels, either side, do they match?

check the bearing on the gantry that supports the Z screw, ensure this is loose, if it is too tight it can bind up the Z screw

3

Thanks, I will take a closer look at the gantry and screw when I get home. The Neo has a single stepper motor and a single screw on one side. I did check that the gantry wasn’t loose and not staying level as it moved up and down, but I didn’t have a technical way to do it. I just tried to wiggle it. I imagine that a small wiggle I didn’t perceive could be causing some of my issues.