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C2557 (bizhub 750i)
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Contents
Trouble type | C2557: Abnormally low toner density detected black TCR sensor |
Rank | B |
Trouble detection condition | When sampling data is determined in TC ratio calculation control, TCR sensor output is higher than a predetermined value for a predetermined number of times in a row even though there is toner in the sub hopper. |
Trouble isolation | – |
Relevant electrical parts | -Developing unit/K -Toner cartridge/KPH unit -Toner empty sensor/K (PS31) -Toner cartridge motor/K (M25) -Toner supply motor/K (M6) -Expansion control board (EXCB) -CPU board (CPUB) -Base board (BASEB) |
Procedure
- Perform image troubleshooting procedure if image density is low.
- Reinstall the developing unit/K.
- Reinstall the toner cartridge/K.
- Check the connector between the developing unit/K-relay CN252-relay CN25-EXCB CN4EX for proper connection and correct as necessary.
- Check the connector between EXCB CN1EX-BASEB CN11E for proper connection and correct as necessary.
- Check the connector between EXCB CN2EX-BASEB CN12E for proper connection and correct as necessary.
- Check CPUB for proper installation and correct as necessary.
- M25 operation check
- Control signal: EXCB CN11EX-1 to 4
- Location of electrical component: 15-P
- M6 operation check
- Control signal: EXCB CN10EX-16 to 19
- Location of electrical component: 23-P
- If the toner empty sensor and its surroundings inside the sub hopper are dirtied with toner, clean them.
- Replace the developing unit/K. (Part# ACV803D)
- Replace EXCB. (Part# AC74H00501)
- Replace CPUB. (Part# ACV7H02P02)
- Replace BASEB. (Part# ACV7H02101)