Savin C3030
SC 553 is a fuser overheat error. If you have a fuser great, but you will still have to reset the code. Clear modes, 1, 0 ,7, press and hold clear/stop key. Menu will change, select copy sp. From there, select 5, (mode), scroll till you get to 5810. Select it, and press execute, then exit back to copy sp. Select 7 (data log) then scroll until you get to 7807. Select it, and press execute. Exit all of the way out, and recycle the power.
If it comes to ready, great. Try it. If it codes out again, you have a problem, possibly thermisters, (in the fuser), power supply getting stuck on, I/O board not regulating the power supply. Could be any of these things.
But start by resetting the code. Could be a a thermister got some toner stuck under it, and the other thermister detected a difference. It really could be that easy.