Epson FX 890 Service Manual - Page 47

FX-1180/FX-880 Service Manual Chapter 3 Troubleshooting Table 3-13. Repairing the Printer Mechanism (continued) Symptom Cause Checkpoint w Problem: Self test printing is not executed. A particular dot is The printhead is Measure the printhead coil missing. defective. resistance. It should be about 8 ohms. If the printhead is shorted, check the drivers on the main board. Check if the head wire is broken. The printing is too The printhead is Check if the head wire is light, or the print defective. broken. density is uneven. The platen gap is not Set the gap adjustment properly adjusted. lever to the first position, and check for the correct platen gap, 0.365 ± 0.015. w Problem: Paper is fed abnormally. The printer tries to Foreign matter is Check if any foreign matter print, but paper is lodged in the paper is lodged in the paper path. not fed or not fed path. constantly. The PF motor dose Check if any foreign matter not drive the is lodged in the mechanism. mechanism. The PF motor is Measure the motor coil defective. resistance. It should be about 16 ohms. If the motor is shorted, also check the drivers on the main board. w Problem: Ribbon operation is abnormal. The ribbon is not The ribbon cartridge is Remove the ribbon cartridge turning. defective. and check if the ribbon feeds normally as you turn it manually. Foreign matter is Check if the RD ratchet lodged in the gears. rotates as you manually move the carriage right and left. The ribbon feeds properly only when the carriage moves in one direction (i.e., it fails to feed when the carriage moves in the other direction). The planetary gear in the ribbon drive gears is defective. Move the carriage manually, and check if the ribbon feed gears turn in reverse and engages with the gear. Solution Replace the printhead, (and drivers , if necessary). Replace the printhead. Replace the printhead. Adjust the platen gap. Refer to Chapter 5. Remove the foreign matter. Remove the foreign matter. Replace the PF motor, (and drivers , if necessary). Replace the ribbon cartridge. Remove the foreign matter. Otherwise, replace the ribbon feed mechanism. Replace the ribbon feed mechanism. Rev. B 3-17