Trying to get the one I just bought working myself. If you have one your parting out and want a quick sale I need some cartridges, namely a key cartridge and italic & script font cartridges. Willing to pay if I can afford them. I also need a copy of the manual. I have searched the net for information and these CNCZone guys seem to know more about it then anyone else. You came to the right place. My knowledge on these is limited; however, I used to work on both computers & tv's. First thing to do is to try and determine if it is electrical or mechanical. Turn it on and see if the monitor is working. Do this by turning both the brightness & contrast fully clockwise. You should have a green full screen "raster". This indicates that the tube high voltage circuits, MB & power supply are working. If not, try another power cord. No raster, cursor tic mark, or a green line indicates Mb or High Voltage problems. If there are also words on the screen the computer may be working right, try entering something from the keyboard and see if there is a screen response. if not, try using another keyboard. Another simple test is to turn the machine off and pull the cartridges out and re-insert them . Sometimes the cartridge traces get corroded. Beyond that, its probably a bench job. Hope this helps...rereading your post, it seems your asking more about the operational side than for an inop machine. I will leave that to some one more familiar with cnc & engraving.