I take it from your responses that you are not well versed servicing the machine. No crime in that, just makes for a challenge as there is much to be...
There can be numerous causes for developer bead carry over on the 510. Start off by cleaning the machine. Test the erase LED, check for scratches in...
As I know the IBT dont have ATC sensor.
Check inside of machine for toner, developer leakage or ,and for gears or clutchs contaminations with toner,...