I'll try to give you a short checklist - if anyone has additional ideas please feel fre to update:
00 check Centronics cable
1.0 read specification of Centronics input interface of interface board (
voltage level/ ranges for hi/low signal)
1.1 measure logical level on changing output on "no load" state ( cable
not connected to board but to PC)
1.2 connect cable to board and measure hi and low under load -the
current sink of the board might lower the voltage level of the
signals
Some newer Mainboards use Centronics drivers for notebooks which are specified with lower high level, so this check should compare the incomming signal with the required levels. -> if this is ok the interconection between PC and controlboard should be right
2.0 Take a Mach III template that is made for Milling -
2.1 Check your MachIII adjustments for the channel / axis
2.2 to make sure, there is a high low signal change on step watch your
Mach output monitor and compare with Centronics pin output
( take care of e-stop or other disenabeling signals - ( limiters or
reference switches)
If there is no fully comparability between MachIII monitor and pins
check the Centronics installation ( adresse(s) if you have several -
did you use the right?)
3.1 I had a case that Mach trial was installed but didn't work 100% what
means the pulsor (realtime clock reference which is placed below the
windows core) was not working succesfully what means
reinstallation, but this is a bit difficult for the ineffective part ist not
easy to uninstall - you perhaps should try to contact you dealer to
help with - or change to EMC
4.1 Anything works fine until now? You have your steppers left as a failure
source - are you able to measure a current trough both of the coils
within a series of 4 Steps ( your Amp should be programmed in fullstep
mode for this). If not, you should check the connection scheme - beep
through both coils -
measure coil resistance ( compare with spec and connect correctly!)
HJ
Why reach for speed, when you could have precision instead!!!