Service manual

4 • Troubleshooting/Diagnostics
DM300c/DM400c/DM475 Service Manual (SV61801 Rev. D)
4-3
Table 4-2 Keyboard and Display Faults
Fault Checkpoints Possible Causes/Solutions
Keyboard
failure. Does not
respond.
Wiring from keyboard to J130A. Keyboard
PCB.
Poor connection at keyboard, wiring and con-
nection at Main Logic Board, J130A.
No display. Machine may be in sleep mode. Is front panel
LED orange?
Press any key to wake unit.
Check display contrast. Adjust display contrast as required.
Machine not getting power. Power cord not plugged in. Power cord plugged
into a switched or defective outlet. Try another
wall outlet. If unit is plugged into a power strip,
move the power cord to a functioning wall out-
let.
No display, front panel LED off, but print head
initializes at start up.
Check connector J130B (next to J130), and
harness to J130B.
See Table 4-1 for power ON an initialization
faults.
Display does not
change.
Meter appears to be “stuck” on the same dis-
play for an extended period of time.
Power cycle the meter to reboot and start over
.
4.2 Troubleshooting Tables