Oki B721 Maintenance Manual

Oki Data CONFIDENTIAL
45487001TH Rev.1
6-30 /
6. Troubleshooting procedure
6.5.2 Preparation for troubleshooting
Note! When replacing the PU/CU board, load the EEPROM chip contents of the
old board first, and copy them to the new board upon completion of the
replacement. (Refer to section 4.4.1 Precautions when replacing the engine
control board.)
(1) LCD display error ...........................................................................................6-31
(1-1) LCD does not display anything. ........................................................ 6-31
(1-2) Error message related to the control panel ......................................6-32
(1-3) “RAM checking” or “Initializing” remains displayed. .........................6-32
(2) Abnormal operations of the printer after the power is turned on ....................6-32
(2-1) Any operation does not start at all. ...................................................6-32
(2-2) Abnormal sound is heard. ................................................................6-33
(2-3) Bad odors are generated. ................................................................. 6-34
(2-4) Rise-up time is slow. .........................................................................6-34
(3) Paper feed jam (Error 391: 1st Tray). ..............................................................6-48
(3-1) Jamoccursimmediatelyafterthepoweristurnedon.(1sttray) ......6-48
(3-2) Jamoccursimmediatelyafterthepaperfeedisstarted.(1sttray) ...6-48
(4) Feed jam (Error 380) ...................................................................................... 6-49
(4-1) Jamoccursimmediatelyafterthepoweristurnedon. .....................6-49
(4-2) Jamoccursimmediatelyafterthepaperfeedisstarted. ..................6-50
(5) Paper feed jam (Error 390: MP Tray) .............................................................. 6-51
(5-1) Jamoccursimmediatelyafterthepoweristurnedon.
(Multipurpose tray) ...........................................................................6-51
(5-2) Jamoccursimmediatelyafterpaperfeedisstarted.
(Multipurpose tray) ...........................................................................6-51
(6) Paper running jam (Error 381) .......................................................................6-52
(6-1) Jamoccursimmediatelyafterthepoweristurnedon. .....................6-52
(6-2) Jamoccursimmediatelyafterapaperistakenintoprinter. .............6-53
(6-3) Jamoccursinthemiddleofpaperrunningpath. ..............................6-54
(6-4) Jamoccursimmediatelyafterpaperhasreachedthefuser. ............6-54
(7) Paper unloading jam (Error 382) ....................................................................6-55
(7-1) Paper unloading jam occurs immediately
after the power is turned on. ............................................................6-55
(7-2) Paper unloading jam occurs after a paper is taken into printer. ........6-55
(7-3) Paper unloading jam occurs in the middle of paper running path. ..6-56
(8) Two-sided printing jam (Errors 370, 371, 372, 373 and 383) ........................6-56
(8-1) Two-sided printing jam occurs immediately
after the power is turned on. .............................................................6-56
(8-2) Two-sided printing jam occurs during taking in the paper
into Duplex unit. ................................................................................ 6-56
(8-3) Two-sided printing jam occurs during transporting paper inside the
Duplex unit. .......................................................................................6-57
(8-4) Paper is not supplied from the Duplex unit to the regist roller. .........6-57
(9) Paper size error (Errors 400 and 401) ...........................................................6-57
(9-1) JamoccurswhenpaperendislocatedneartheIN1sensor. ........... 6-57
(10) Fuser unit error (Errors 167 to 177) ...............................................................6-58
(10-1) Error occurs immediately after the power is turned on. ....................6-58
(10-2) Error occurs approx. 1 minute after the power is turned on. ............. 6-58
(11) Motor fan error (Errors 122, 127, 128, 918 and 051) .....................................6-59
(11-1) The low voltage power supply fan does not rotate immediately after the
power is turned on. ........................................................................... 6-59
(11-2) Duplex fan does not rotate during the Duplex printing. .....................6-59
(11-3) All fans of the printer do not rotate. ..................................................6-60
(12) Print speed is slow. (Performance is low.) ...................................................... 6-60
(12-1) Print speed decreases. ..................................................................... 6-60
(13) Option unit cannot be recognized ..................................................................6-60
(13-1) Option try unit cannot be recognized................................................6-60
(14) LED head cannot be recognized. (Errors 134) ...............................................6-61
(14-1) Errors 131 to 134 (LED HEAD Missing) ...........................................6-61
(15) Toner cartridge cannot be recognized. (Errors 543) ......................................6-62
(15-1) Error caused by the consumable items. ...........................................6-62
(15-2) Error caused by the toner sensor .....................................................6-62
(15-3) Error caused by the defective mechanism .......................................6-63
(16) Fuse cut error (Errors 155) ...........................................................................6-63
(16-1) Fuse cut error ................................................................................... 6-63
(17) Humidity sensor error (Error 123) ..................................................................6-64
(17-1) Humidity sensor error ...................................................................... 6-64
(18) Wiring diagram ............................................................................................... 6-65

Oki B721 Specifications

General

Print Technology	LED
Resolution	1200 x 1200 dpi
Processor	533 MHz
Memory	256 MB
Connectivity	USB, Ethernet
Duplex Printing	Standard