Sidewinder X1 Stepper driver issue

Hi All,Repairing my Sidewinder X1 various issues like cable breaking because of constant movement of bed etc. However after opening bottom cover to check cables I notice the Z Axis stepper driver at an angle so only one row of pins are seated. I test the Z Axis and no issues. However thinking it more logical for the driver to be seated so both rows of pins are fully seated i push the stepper full down to seat pins. Almost instantly the heat sink on driver get very very hot. So I pull driver and i don't see any issues like shorted pins etc and seat it again and it gets hot. i then angle the driver like when I first saw it so only one row of pins is seated. the Z Axis is working fine but this is very odd and allows the driver to fall out with vibration etc. Can any one explain this issue as I've never seen it before. Many thanks