MKS board losing power after endstop installation
Photo Credit: Courtesy of 3DStockPhoto ( image)

Have you tried plugging in the plugging the Z and/or Y end stops into the X position? This could tell you if it's actually the end stops or the board.

EDIT: Also, if the Z and/or Y end stops seem to work just fine in the X position, ensure you have the X position filled and try the other end stops in the Z & Y positions. It may be a case where having multiple positions on the board filled might be causing you an issue. This would point back at the board and not the end stops.