Need a used one just to test the machine. also firmware . .i have problem with tp1-tp8. one tp 3 show 1 one tester. I took it to fix and changed some transistor, c4550 , c1475. Machine start and boot, then error 200 memory board. then a led light came on the mainboard.I connect all cables to sliding board except from sliding board to print head, and a led light on the sliding board. When i shut down and power still led light on sliding board went off slowly , but on the mainboard is still on, as long i have the power connected, panel screen power off normal, mainboard led is always on. I could get my parameters out. Can you suggest. Thanks again