EZTrak power on issue

Hi. We have an old EZTak DX 2 axis knee mill. An interesting problem has shown up lately. When I power up the machine, both x&y axis start heading home at once. It will do this until the PC boots. Many times, the PC won't start booting, so I power off the machine and try again. As soon as the PC boots, the axis movement stops.

I have no idea as to where to begin with this. Any ideas?

Thanks.