Firstly welcome to the forum.
Secondly typing in upper case is consider to be shouting, and will cause offence as it is considered impolite.
You should be able to get assistance from Amadeal who are the UK Syil distributers and appeared to me on my visit when researching what I should buy, to be very friendly and helpful.
Two years is a long time, and you do not say whether you bought it new from a dealer, used from a dealer, or used privately, and this might make a difference.
If there is not so much as a twitch, and you have had ‘parts’ replaced (which parts), it would seem to be computer /computer comms related. What type of PC is it. Have you tried a different parallel cable? Have you tried a different PC tytpe? Are you sure that the Mach3 software and drivers are installed correctly? Is the PC dedicated and disconnected from any network?
Have you tried Mach Support (you do have a full, licensed copy don’t you – I believe without a valid licence Mach3 is in Demo mode only)?