Q53 should be a 2n6043 transistor q54 is an mps-u45 but you will have to get the replacement cent-u45 as the other is damn near impossible to find. I have a Star race which was the pin produced just before yours and I'm pretty sure that the driver boards are all the same for the system80 machines. Do you have a manual? If so you can look all the transistors up in it and see what all do. I will look in the repair guides and give you the possible replacements for your transistors etc.. if you just tell me what they are or where they are located.