Programmer Tips - Epson LQ 1050 - B/W Dot-matrix Printer Technical Manual

If you want to test the printer without a host computer, then set dip SW1 as follow:
DIP SW1
OOH
OIH
02H
03H
04H
05H
06H
07H
08H
09H
OAH
OBH
OCH
ODH
OEH
OFH
10H
1 IH

5.2.7 Programmer Tips

(2) If you want to skip any file (or program), then press the ESC key.
If you want to return to a previous file (or program), then press DEL key.
Table 5-2. Off-Line Diagnostics
Check & check
RAM CPU
Address/Data line Hi/Lo
Home position sensor check
Paper end sensor check
F/T sensor check (F/T: Friction/Tractor)
Control panel SW check
Head drive Transistors short circuit check
Head drive voltage (+ 24) check
Motor drive voltage (Vu) check
Paper feed motor phases output
Carriage motor phases output
Plunger solenoid On/Off
Plunger drive voltage change drive/hold
Paper feed motor drive voltage change drive/hold
Plunger enable line change disable/enable
Interface control line Hi/Lo
Carriage motor current change line Hi/Lo
All selecType LED On/OFF
F U N C T I O N
5-8