Epson FX-870/1170 - Manual (Page 59)

Troubleshooting
Problem Isolation
Most printer problems can be corrected by replacing the defective unit. First, identify the
problem from the symptoms you observe using the table below. Then, follow the instructions in
the corresponding flowchartto correct the problem.
Table 3-8. Symptoms and Flowchart References
Flowchart
Symptom Possible Problems . or Solution
Printer dead, or abnormal
l
Possible power supply voltage problem. See
operation at power on.
l
A motor or printhead may be shorted. Chart 1.
. CO94 MAIN board may be bad.
Carriage does not move, or
l
Something in the mechanism may be catching. See
carriage operation abnormal.
l
Sprocket or ribbon driie gears may be stuck or broken. chart 2.
l
CR HOME sensor may be bad.
l
Carriage motor may be bad.
l
Driver for CR on CO94 MAIN board may be bad.
Paper does not feed, or
l
Something in the mechanism may be catching. See
paper feeds abnormally.
l
Paper feed motor may be bad. Chart 3.
l
for PF on CO94 MAIN board may be bad.
Self-test printout has poor
l
Platen gap may be incorrect.
quality.
l
Printer may need bidirectional adjustment. See
l
Head cable may be bad. Chart 4.
l
may be bad.
l
Printhead on CO94 MAIN board may be bad.
Printing is darker on one
l
Platen may not parallel to carriage guide shaft. platen
side of the page than on gap adjustment.
the other side.
Printing is intermittently
l
Ribbon may be bad.
dark and light.
l
Ribbon mask may be damaged. See
l
Sprocket or ribbon drive gears may be stuck or broken. Chart 5.
l
Platen gap may be incorrect.
Data from the host is
l
Printer default settings may be wrong for application.
printed incorrectly. (Host is
l
Interface cable may have a problem. See
assumed to have checked
l
Software settings may be incorrect for printer. Chart 6.
out OK another printer.)
l
Possible problem with ROM or CO94 MAIN board.
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