Geeetech

Hi all ive has my printer for 2 weeks now and its been going ok and just recently i have gotten the usb working but after 4 print using usb the printer is doing a weird thing where it looks like it is skipping layers or something i dont know really, i think its extruding fine it just doesn't print right any help is appreciated

https://www.youtube.com/watch?v=tJXOjH7cOuk

the first few layers go on fine then it just goes really high and puts dots everywhere

its not to far away i have triple checked
so im stumped.
it might be firmware due to the usb and maybe i messed up a setting i dont know

it stays to low and then shoots up way to high i dont know whats up with it

looks like you have the Nozzle set too low, the plastic is backing up in the nozzle set your z to 0.3mm and set the range between 0.2 mm and 0.3mm make sure you purge the Nozzle before you start you may also have a clogged Nozzle... Dust and Dirt that gather on the filament will cause Nozzle clogging... best way to deal with this is a glasses cleaning cloth with a few 3in1Oil drops on it and put that in a clip what I do now is buy cleaner filament.
also measure the thickness of your filament default is always set to 3.00MM but most are now 1.75mm but that varies +- 0.16mm and It dose affect the extrusion rate..
Start Gcode
G1 E1.5 F250; (Small retract to help with blobbing on next line)
G28; (home all axes, forces a bounce in the center on the A30)
G1 Z5 F5000 ; (lift nozzle)

; Adapted from MP Select Mini V2 profile in Cura
G92 E0;(Reset the extruder to 0, no movement on this)
G0 Z1 E5 F500;(Move up and prime the nozzle)
G0 X8 Y12 Z0.3;(Move outside the printable area)

; Movement and priming wipes to ensure a clean start
G1 Y80 E16 F500;(Draw forward - a priming/wiping line to the rear)
G1 X9.5 Y14 E32 F500;(Draw backward - more priming/wiping with extra volume)
;G1 E-.5 F250;(Small retract if needed)

G92 E0;(Zero the extruder)
End code