Service manual

EPSON LX-300+ Revision A
Troubleshooting Troubleshooting 63
3.2.4.4 Printhead Driver Check
Simple check of the printer driver (Q3 ~ Q11) can be done by the following
method.
Table 3-13. Printhead Driver Check
Item Operation Specification
Printer driver
(Q3 ～ Q11)
1. Set the multimeter to the resistance
measuring range.
2. Connect the one side of the probe to
the base of the transistor.
3. Connect the one side of the probe to
emitter of the transistor.
The resistance
should NOT be
“0” or infinity.