Bad calibration cubes and running out of ideas

[HoloPuff]

My cubes are really bad and I don't know what to do anymore.

Printer: V2.4 LDO 350mm with Revo 0.4mm nozzle, StealthBurner, Tap
Max acceleration set to 3000
Extruder rotation_distance has been calibrated and verified

Material: ABS (AMZ3D) gray
Left Cube: nozzle=240c, extrusion multiplier=1, cooling fan = 50%
Right Cube: nozzle=230c, extrusion multiplier=0.9, cooling fan = 100%

I also tried 250c and it looks the same. The bridge inside the cube is also really bad and came out as pretty much a blob.
What now? I've been meeting around with this printer for months. Replaced most of the printed parts, upgraded to tap and canbus, made sure everything is tight, gantry is squared, I can get a decent cube

Do I replace the hotend? I'm getting really discouraged here.

 

[Yezariael]

I would start wtih hardware and doublecheck if everything is tight, all the grub screws and belts okay. Then, did you follow the Tuning Guide step by step?

 

[claudermilk]

I just finished re-calibrating my printer after things went sideways and my cubes looked something like yours. I checked all the bolts again, even though I was pretty sure they were tight; I found a couple that might have been a bit loose and that resolved my Z wobble artifacts. I also threw out all my slicer settings and started from scratch with the Andrew Ellis ones as a baseline then ran through his calibration routine again. Now the printer is working beautifully.