Sorry for my bad english...

I got 4 osi machines from a car workshop. Three of them was C3 with 8" floppys and HD. One of them in C3 OEM with 8" floppys.
I tryed to start the oem machine yesterday. I got D/H/M? on the screen. I have no floppy or hd installed so i tryed to enter M. The only response i got was that the prompt jump down just like i pushed return. The same if i try another key. The prompt just jump down to the next line. I try to short td and rd from the terminal and the cable and terminal talked fine to it self.
I have processor board, three memoryboard and floppykontroller installed. I tested processor board and memory from one of the other machines but i have the same fault. Eaven an other terminal and cable. Same fault.
What is wrong?
Kristoffer from Sweden.