IBM 4247 Maintenance Information page 242

18-Wire Printhead Wiring (Models A00, 001, and 003)
The printhead is electromagnetic and has two columns which contain 9 wires. The left column (viewed from the
platen or paper side) is the B side with wire 1B at the top. The right column is the A side with wire 1A at the top.
The A side is raised and lowered (by an electromagnet), to increase print quality. Needle 5B is used for AFTA
paper thickness measurements. The printhead is connected to the logic board by a 22-pin cable and a 26-pin
cable.
18 Wire Printhead
22 Pin
Connector
Ribbon Lift
Connector
26 Pin
Connector
Figure 25. 18-Wire Printhead Wiring (Models A00 and 001)
RESISTANCE MEASUREMENTS
Note: Allow the printhead to cool before taking resistance measurements.
Table 29. 18-Wire Printhead Resistance Measurements
Part
Print Wire Coil
Not
Used
Pin 1
Pin 1
Resistance
5 Ohm ±10%
Temperature
20°C (68°F)
Chapter 3. Circuit Diagrams
242