Power Supply Unit Failures - Intermec EasyCoder PX4i Service Manual

Chapter 17 — Troubleshooting

17.5 Power Supply Unit Failures

218
Description:
The printer refuses to print.
• The message "Temperature high please wait" (FP) or "Printhead hot"
(IPL) appears in the display window.
The power supply unit contains wires and circuits with dangerous
voltages. For safety reasons, it is strictly forbidden to try to repair a
power supply unit or to replace a blown fuse. Generally, in a primary-
switched power supply, a blown fuse is an indication that components
in the power supply has been damaged or degraded. Even if you could
get the power supply working by replacing a fuse, there is a risk that it
soon will fail again and more components will be damaged. Therefore,
whenever a fuse blows, always replace the entire power supply unit.
Possible Causes and Suggested Remedies:
• Power Failure Interrupt signal activated because of a Power Supply
overload.
- Too high a temperature in the power supply unit, for example caused
by 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 pro-
tection switch.
Leave the power on and wait for the power supply to cool down (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 13).
Description:
The printer stops working or functions are unstable.
• The power LED is unstable, weak or not lit..
Possible Causes and Suggested Remedies:
• Wrong or missing 24 VDC voltage from power supply.
- Check the 24 VDC output on connector P2.
- Check the cables between the power supply unit, the driver board,
and the CPU board. If the cables are OK, try to fi nd out whether
the power supply or driver board is faulty (also see Chapter 17.6).
Replace the faulty unit.
- If there is no 24 VDC and you can rule out that the PSU has been
shut down because of overheating (see above), check for a blown fuse
in power supply. If any of the fuses F1 or F2 has blown, replace the
entire power supply unit. Do not replace a blown fuse and do not
attempt to repair the power supply unit (see "Warning" notice above).
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