mper selector for
AC input and use it properly.
Make sure to use the jumper on appropriate models.
2
Wrong input connection? For example, AC (L) or
(N) is connected to FG terminal.
Check and correct the input connection if necessary.
3

AC voltage is not applied to
power supply correctly.
Is external fuse blown?
1) If the built-in fuse is blown, return the power supply to us for repair.
2) If the built-in fuse has no problem, change the external fuse to one that can withstand the
inrush current of the power supply and has the same voltage/current rating as the built-in fuse.
4
Is the wiring to the load correct? (For example, +V
and V are connected in reverse).
Correct the connection.
5
Check to see if the wiring to the load shorted
together accidentally.
Correct the problem by checking the wiring isolation.
6
1) Wrong Connection.
2) Loosened terminal screws.
Terminal screws have loosened?
Tighten the terminal screws.
7
Is output voltage adjuster (trim pot) turned too far
clockwise?
Switch off the power supply, turn output voltage adjuster to its maximum counterclockwise, and
wait for 5 minutes before switching on the power supply again.
8
Sensing terminal screws have loosened?
Tighten the screws.
9
Is sensing wiring correct?
Connect the sensing wires according to the instruction manual.
10
Overvoltage protection has
been operated.
Are sensing wires disconnected?
Re-connect.
11
Overcurrent protection has
been operated.
Are there any chances that the drawing current has
become greater than the rated output current?
Check the rated output current of the power supply used and measure the current actually
drawn from power supply.
12
In case of AC/DC power supply: Is RC terminal
connected to RCG terminal?
Connect (short circuit) RC terminal to RCG terminal.
13
Remote ON/OFF is off.
In case of DC/DC power supply: Is RC terminal
connected to V input?
Connect (short circuit) RC terminal to V input.
14

Power supplies used in series
operation.
Are the power supplies used allowed series
operation?
Change the power supplies to those allowed series operation.
15
Is the ambient temperature higher than the
specified maximum operating temperature?
Switch off the power supply and cool it down to room temperature before switching on again.
16
Thermal protection has been
operated.
Are there any obstacles around the power supply
that are physically stopping the built-in cooling fan
or the air flow?
Remove the obstacles, switch off the power supply, and cool it down to room temperature
before switching on again.
17
Is there water splash on power supply?
Keep power supply away from water splash!!
18

There is condensation on
power supply.
Are there any sudden changes in ambient
temperature?
Use power supply where ambient temperature is stable.

SEE BACK
Input Side
Out
p
ut Side
Other
TROUBLESHOOTING
TIPS
RETURN POLICY: All products carry a
manufacturers warrantee. Defective products must
be returned to Power Factor within the warrantee
period. Power Factor will replace or repair all
defective products, at Power Factors option. Items
returned in re-saleable condition will be replaced.
Used items will be repaired. Call for RMA number.



2. In case of Abnormal Output Voltage (Too High, Too Low, Unstable) what to check
No.
Possible Causes
Check Points
Solutions
1
Is output voltage adjuster (trim pot) turned too far
clockwise?

Turn output voltage adjuster counterclockwise.
2
Is there any external voltage from another source
applied to the same load?

Change the load circuit so that there will be no external voltage applied through the load to the
power supply.
3

Output voltage is set too high.
Has the sensing terminal screw loosened?
Tighten the screws.
4
Is input voltage lower than the minimum specified?
Measure the input voltage.
5
Input voltage is too low.
Is wave form of input voltage distorted?
If distorted, use AVR for input.
6
Output voltage is set too low.
Is output voltage adjuster (trim pot) turned too far
clockwise?
Turn output voltage adjuster clockwise.
7
Is voltage drop caused by long output wires to the
load?
Make the output wires shorter.
8
Is voltage drop caused by thin (high-AWG) output
wires to the load?
Use thicker (low-AWG) wires.
9
Is there any bad connection?
Check the connection.
10
There is a voltage drop
caused by output wires.
Have the terminal screws loosened?
Tighten the screws.
11

Overcurrent protection has
been operated.
Are there any chances that the drawing current has
become greater than the rated output current?
Check the rated output current of the power supply used and measure the current actually
drawn from power supply.
12
Are the sensing wires too long?
Use electrolytic capacitor between output terminal (±V, ±M) and sensing terminal (±S).
13
There is oscillation caused by
remote sensing.
Are the sensing wires twisted?
Twist the wires.
14

Minimum output current
required is not drawn.




In case of some multiple output type power
supplies, a minimum drawing current is required on
+5V output.
Check to see if there is minimum load requirement
for the power supply.
1) Draw a minimum current required on +5V.
2) Use a power supply whose +5V output has no minimum drawing current requirement.

When output voltage is too high.
When output voltage is too low.
When output voltage is
unstable.