{"id":26255,"date":"2025-06-10T14:02:32","date_gmt":"2025-06-10T14:02:32","guid":{"rendered":"https:\/\/apps.kmbizhubvcare.com\/bizhubtroubleshooter\/?post_type=epkb_post_type_1&p=26255"},"modified":"2025-06-10T14:29:23","modified_gmt":"2025-06-10T14:29:23","slug":"c2551-c2553-c2555-c2557-c4651i","status":"publish","type":"epkb_post_type_1","link":"https:\/\/apps.kmbizhubvcare.com\/bizhubtroubleshooter\/?epkb_post_type_1=c2551-c2553-c2555-c2557-c4651i","title":{"rendered":"C2551, C2553, C2555, C2557 (C4651i)"},"content":{"rendered":"\n

Contents<\/h2>\n\n\n\n
Trouble type<\/td>C2551: Abnormally low toner density detected cyan TCR sensorC2553: Abnormally low toner density detected magenta TCR sensorC2555: Abnormally low toner density detected yellow TCR sensorC2557: Abnormally low toner density detected black TCR sensor<\/td><\/tr>
Rank<\/td>B<\/td><\/tr>
Trouble detection condition<\/td>When sampling data is determined in TC ratio calculation control, TCR sensor output is lower than a predetermined value for a predetermined number of times in a row even though there is toner in the toner cartridge.<\/td><\/tr>
Trouble isolation<\/td>–<\/td><\/tr>
Relevant electrical parts<\/td>Imaging unit\/C,M,Y,KToner supply motor\/YM (M4)Toner supply motor\/CK (M5)CPU board (CPUB)Base board (BASEB)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Procedure<\/h2>\n\n\n\n
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  1. Perform image troubleshooting procedure if image density is low.<\/li>\n\n\n\n
  2. Reinstall the imaging unit.<\/li>\n\n\n\n
  3. Check the connector between the imaging unit\/C-relay CN5-BASEB CN14E for proper connection and correct as necessary. (C2551)<\/li>\n\n\n\n
  4. Check the connector between the imaging unit\/M-relay CN8-BASEB CN14E for proper connection and correct as necessary. (C2553)<\/li>\n\n\n\n
  5. Check the connector between the imaging unit\/Y-relay CN7-BASEB CN14E for proper connection and correct as necessary. (C2555)<\/li>\n\n\n\n
  6. Check the connector between the imaging unit\/K-relay CN6-BASEB CN14E for proper connection and correct as necessary. (C2557)<\/li>\n\n\n\n
  7. Check the connector between M4-BASEB CN13E for proper connection and correct as necessary.<\/li>\n\n\n\n
  8. Check the connector between M5-BASEB CN13E for proper connection and correct as necessary.<\/li>\n\n\n\n
  9. Check CPUB for proper installation and correct as necessary.<\/li>\n\n\n\n
  10. M4, M5 operation check\n