ive got one of these that the customer prints to it with a paralle cable. right now everytime they send anything to it on the machine it says processing data on the screen for about 3 seconds then goes back to the ready to recieve data but never prints anything out and the print job is no longer in the print que. i have tryed reloading the print drivers reloading and updating the software and have even replaced the sh-pcb with no luck. the machine works fine other than this issue and is not throwing any codes at all. any suggestions would be great. thank you in advance