Power Supply Unit Failures - Intermec EasyCoder 601 XP Service Manual

17.5 Power Supply Unit
Failures
IMPORTANT!
For safety reasons, it is strictly forbidden
to try to repair a power supply unit or to
replace a blown fuse.
WARNING!
The power supply unit
contains wires and circuits
with dangerous voltages up
to 380V.
Intermec EasyCoder 601 XP – Service Manual Ed. 2
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.
• Grounding wire missing (certain printers only).
- Fit an extra grounding wire as described in Technical Bulletin
No. 42/1997.
• Power Supply overload.
- Too high a temperature in the power supply unit, e.g. 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).
• Cooling fan does not work.
- Repeated power supply overloads at normal ambient
temperatures 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 approximately +45 ° 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
available 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%).
Chapter 17 Troubleshooting
132