Seeburg USC1 No select single, won't take key press

I have a USC1 and was working on a LC1. I swoped out the DDC in USC1 to test out the LC1. And so it had the same problem it was doing, and I put back the DDC back in the USC1. Later that day I turned on the USC1 and now the select single light does not turn on, nor any number section lights light up when I press numbers. Now I'm stumped. All I did was take it out and used it on another machine and then put it back in. Shame too, USC1 has all ways worked for me.
Now if unplug the totalizator from the DDC, the make selection light comes on, and I can press the first 2 numbers and nothing happens on the 3ed. Any suggestions?

What's a LC1 ?? You NEVER want to run any "MicroLog" Seeburg without a plug in the "Totalizer jack", in the DCC !!
Swapping components can ruin two components, if failure was caused by external problems--
If you have electronic skills, a good copy of the Service Manual, and a copy of my "Seeburg MicroLog Trouble shooting Guide" should help you -- PM me if you wish to purchase my guide--see above for the Service Manual, if you need one--
Ron Rich

Oh, I don't know what I was thinking, er I meant SPS not LC1. Thanks for your quick reply. I do believe the usc1 and SPS 160 dcc are compatible with each other right? I don't think it's the dcc, Today I tryed a known working one in it and it dose the same. I also tryed swiping the black boxes, so it's not the black box eather. I'm stumped. I'm gonna check the entire machine for loose connections tomorrow maybe I'll find some quarters on the floor.

All DCC's, with the exception of the DCC-2 CODE A, are interchangeable. The negative supply fuse, should be a 6/10 SB amp in LS-3 or USC models--8/10th SB, in all others. The 15 amp FB, should be changed to a MAX of 7.5 FB in all models. Ron Rich