Specifications

Chapter 4: Troubleshooting 7193 Service Guide
August 199834
Field Effect Transistors (FETs))
Field Effect Transistors (FETs) are located on the PC board and can be used to diagnose
motor and printhead problems. There are a maximum of 14 FETs located on the PC Board
assigned to the following items:
• Feed Stepper Motor Drive: five FETs (Q1, Q8 Q9, Q13, Q14)
•
Knife: four FETs (Q7, Q12, Q16, Q21)
• Thermal printhead: one FET (Q25)
• Cash Drawer 1: one FET (Q5)
• Cash Drawer 2: one FET (Q6)
• Speaker: two FETs (Q11, Q15)
Caution: Electro Static Discharge may damage the PC board. Wear a grounded wrist strap
and use a static mat or other ESD protected work surface whenever you work with the PC
board.
If the resistance across any two pins is less than 1k ohm, the FET needs to be replaced.
Refer to the following illustration for the locations and descriptions of the FETs.