Users Manual Model 656/636 Electrical Trouble Shooting • 45
Electrical Trouble Shooting

Power Up / Sign On / Communications

Problem Probable Cause Corrective Action
Machine fails to power up with no
light present in the AC power
switch.
1) Incorrect power amplitude. 1) Confirm that the AC entry is
configured for the line voltage
intended to be applied to the
machine. Failure to do so can
damage the machine's internal
power supply. Refer to the "Fuse
Configuration".
2) Lack of power to machine. 2) Check that both ends of the power
cord are plugged in securely.
2A) Confirm that the outlet the
machine is plugged into has power.
3) Missing or blown fuse(s) 3) Check that the fuse(s) located
inside the AC entry are present and
intact. Replace as needed. Refer to
the "Fuse Configuration".
Machine fails to power up with light
present in the AC power switch.
1) Unconnected cable / connector
inside machine.
1) Power off and remove the power
cord from the AC entry. Remove
the back cover and inspect the
cables and connectors to and from
the power supply. Refer to the
"Electrical System Schematic".
2) Thermal Control Board unplugged
from the Mother Board
2) Power off and remove the power
cord from the AC entry. Remove
the back cover and reseat the
Thermal Control Board.
Front panel displays no text or
nothing at all.
1) Front panel cable unplugged. 1) Power off and remove the power
cord from the AC entry. Remove
the back cover and inspect the
cable and connectors to and from
the front panel. Refer to the
"Electrical System Schematic".