You need to post the chassis model number (e.g. 25K7191, for example) , and pictures are always helpful 

You must power the monitor with an isolation transformer.    You will damage the monitor (and possibly yourself) without one  
 
  For connecting to a PC, the easist method is to buy an arcade VGA card.  Otherwise you can go the (much) more challenging route and use advancemame (dos) and/or powerstrip (windows) with one of the many compatible cards.