Troubleshooting Procedure; Troubleshooting Guide - Citizen PMU2300III Series Service Manual

3-2. Troubleshooting Procedure

When a fault occurs, confirm its phenomenon, locate the problem in accordance with "3-3. Troubleshooting
Guide", and troubleshoot it as described below.
Find an applicable fault phenomenon in "3-3. Troubleshooting Guide". If there are multiple
Phenomenon phenomena, take all the applicable items into consideration. This will help you locate hidden
problems as well.
Possible causes are listed here. Find probable causes from the list and follow the check method to
Cause
identify the cause of the fault.
Check Method The check method for identifying the cause of the fault is described.
Remedies Take the remedies described in this column.
By following the above-mentioned procedure, you can troubleshoot problems efficiently with fewer
misjudgments.

3-3. Troubleshooting Guide

● Power Supply Failure
Phenomenon
Power cannot be turned
on.
(The POWER LED not
illuminated.)
The high-voltage error is
indicated.
The low-voltage error is
indicated.
The fuse is blown soon if
it is replaced with a new
one.
* If the fuse is blown with the specified AC adapter used, the thermal head or control PCB may be defective. Replace
the defective part with a new one. Check wiring of the interface cable.
Cause
The power cable is not
connected.
The fuse is blown.
(F101 or F103)
The power supply is faulty
(voltage rises).
The power supply is faulty
(voltage drops).
The fuse is blown.
(F102)
The control PCB is faulty.
The circuit drive power is
abnormal.
PMU2300III Series Service Manual
Check Method
−
Check if the specified fuse is
used.
Check the continuity with a
tester.
Check the input voltage.
(Input voltage: 28.3 V or
greater)
Check the input voltage.
(Input voltage: 17.6 V or
smaller)
Check if the specified fuse is
used.
Check the continuity with a
tester.
−
Use a tester and measure
the circuit drive voltage.
- 35 -
Remedies
Connect the power cable.
Use the specified fuse.
Replace the power supply or
adjust it.
Replace the power supply or
adjust it.
Replace the fuse with the
specified one.
Replace the control PCB.
Replace the control PCB.