Hi, I have a new 6003i with 150 copies on it. Ran at customers office fine and at setup. Instant c 7101 code after warming up. Says toner sensor issue. Replaced two new BK developer units. No help. Updated FW. Called hotline twice and local Kyocera rep. Reset front drum/dev relay board. Can get into service mode but can`t run anything because it`s in error state. Closing up machine without dev unit gets different code so i know the front connector for dev unit works on relay board. What should i start with next. Hotline not much help. Feed board, engine board or main board? Any help appreciated.