Chapter 3 — Replacing Parts
EasyCoder PD41/PD42 Printer Service Manual 73
Selected Test Points
All testpoints are marked with silkscreen on the bottom side of the main
board. Some of them can also be accessed from the top side, but are more
difficult to find since they are not marked out.
Test Points on Main Board
Signal Note
24VS +24V supply voltage (to stepper motor), max ±0.3V
5V Logic supply voltage, max ±0.2V
3.3V_x Logic supply voltage, max ±0.2V
1.5V Logic supply voltage, max ±0.1V
GND_x Logic ground
STRB Printhead strobe, toggles high when activated
24V_PH Printhead +24V supply, +24V when printing
STEP Stepper motor clock
RIB Ribbon sensor A/D, toggling when ribbon supply bobbin is
rotating
LTS Label taken sensor A/D, high level when label is sensed
HL Headlift sensor A/D, high level when printhead lifted
GAP Gap sensor A/D, high level in label gap
BM Blackmark sensor A/D, low level in blackmark
RESET_N System reset, high when printer is active
5VE +5V supplied to external ports, max ±0.25V
OC_N Overcurrent on 5VE, low when short circuit on 5VE
CUT1, CUT2 Cutter control, Outputs ({CUT1;CUT2}):
{0;1} – Forward
{1;0} – Reverse
{1;1} – Brake
{0;0} – Stop (high impedance)
CUTHOME Cutter status, high level in home position