Intermec EasyCoder 501 XP & 601 XP – Service Manual
176
Chapter 17 Troubleshooting
17.5 Power Supply
Unit Failures
Description:
The printer stops working or functions are unstable.
- The power LED is unstable, weak or not lit.
- Stepper motors are out of order.
- No or very weak printout.
Possible Causes and Suggested Remedies:
• Missing voltages from power supply.
- Check voltages using the test points on the CPU board (see
Chapter 15.5.
- Check the cable between the power supply unit and the CPU
board. If the cable is OK, replace the power supply unit.
- Blown fuse in power supply. Replace the entire power supply
unit.
• Power Supply overload.
- Too high a temperature in the power supply unit, for example
caused by a defective fan or extreme ambient temperatures
(possibly in connection with large black areas in the print
image, high speed printing and media that require a high
energy level), triggers the automatic overheating protection
switch.
Leave the power on and wait for the power supply to cool off
(may take up to half an hour.) When the temperature returns
to normal, the printer will automatically restart. If the error
persists, examine the power supply (also see Chapter 14.)
- A new fan with higher capacity for extreme operating condi-
tions is available as a spare part.
• Cooling fan does not work.
- Repeated power supply overloads at normal ambient temper-
atures and normal printing conditions may indicate that the
cooling fan at the bottom of the power supply unit is either
defective or out of power. Replace if necessary.
- The fan is controlled by a thermostat and will only run when
the temperature exceeds approxi45°C (+113°F.) If
the replacement fan refuses to run to, the thermostat may be
defective and the entire power supply unit must be replaced.
Note:
When the overheating switch has been triggered, the
fan will be out of power until the printer comes on again.
• Wrong voltages on test points.
- Remove the power supply and disconnect from CPU board.
- Plug in the power cord, but
take care
to protect yourself from
high voltages (up to 380V.) Turn on the power and adjust the
24V and 5.3V in the following order:
Load the 24V with at least 0.3A and trim using potentiometer
R89 to 24V ±5%.
Trim the 5.3V using potentiometer R146 to 5.3V (only avail-
able on power supply unit P/N 1-971601-27 or later.)
- Check the voltage P24 ( 24V when active.) Has to be
enabled.
- Check the voltage V40 (42V ±10%.)
WARNING!
The power supply unit con-
tains wires and circuits with
dangerous voltages up to
380V.
IMPORTANT!
For safety reasons, it is strictly for-
bidden to try to repair a power supply
unit or to replace a blown fuse.