I have my Velleman K8200 sinds 4 years.
Since this week when I press the home button, it no longer returns to its starting position on the y-axis. He centers it and if I press the home button every time, as a test, the x-axis goes nicely to its home, but the y-axis moves up a bit until I finally reach the other side.
Looks like he keeps forgetting the home position.
Never had it before.
Have you physically check the Y endstop ? And/or used Repetier and the g-code M119 ( Endstop States | Marlin Firmware )to get the endstop states ?
Also the cables of the motor and the endstop (continuity chek) ?
the connectors on the motherboard (not shaky) ?
the driver stepper motor (swap it with like the X one to see if the problem go to X ? but be careful to plug them correctly and to disconnect the machine power supply when disconnecting /connecting them. ) ?
…
so if the M119 report the switch “TRIGGERED” but the switch is not “physically” triggered
then you have to look carefully to the switch, on this endstop. (it can be stuck …)
and maybe test the endstop switch manualy with a multimeter on continuity check …
or the cables are defective … ( a short cut)
hopping this is not the motherboard …
Or have you change the firmware ? (try with an original velleman version …)
At this moment i only printed new parts for my printer.
I did’nt print any big objects , but i was focused to try to print different products, PLA, ABS,PETG PLA FLEX e.g.