[X/Y motor not working properly after Z-homing]

Managed to answer myself: burnt my finger on a heatsink when trying to double checking some cables: severe overheating caused faulty movements.

[X/Y motor not working properly after Z-homing]

Hi guys, I am having a problem:

I recently started working at a school with a dusty old UMO. Most functions seem to work properly, but I am having trouble with the motors.

When using Cura to move the X/Y, they are working just fine. But after I do a Z-home, they do not work and start producing electric noises.

The problems: the motors start missing steps. When moving by 100mm for example, they move for 1 second, pause for 1 second, and move for 1 second. This means it doesn't complete the 100mm movement. Also, it starts making noises like a capacitor overcharges and discharges, or something overheats, I am not sure.

Can anyone please help me? The UMO is quite old and rusty and I do not have much experience with it. Any help appreciated!