18 | SAMLEX AMERICA INC.
SECTION 7 | Troubleshooting Guide
7.1 TROUBLESHOOTING GUIDE IS GIVEN AT TABLE 7.1 BELOW
NOTE: This guide is based on operation as a power supply (only DC load is connected -
no external battery or battery backup).
TABLE 7.1 TROUBLESHOOTING GUIDE
Symptom Possible Cause Remedy
ON / OFF Switch is ON
• Switch is NOT lighted
• No DC output
No AC power from the
AC outlet
Internal AC side fuse
is blown
Check AC power is available at the AC
outlet. Breaker feeding the AC outlet may
have tripped.
Open the top cover and check the AC side
fuse. Replace if blown.
If the fuse blows again, the input section is
damaged. Please call Tech Support.
ON / OFF Switch is ON
• Switch is lighted
• No DC output
Unit has shut down due to over
temperature – Temperature of
output transformer windings is:
≥ 105°C ± 5°C / 221°F ± 9°F
Check that the fan is running. If not, the
fan / fan control circuit may have been
damaged. Call Tech Support.
Check that the fan suction vents on the
sides of the unit and the discharge vents on
the bottom of the unit are not blocked.
The unit will reset automatically when the
transformer windings cool down to
≤ 75°C ± 5°C / 167°F ± 9°F
ON / OFF Switch is ON
• Switch is lighted
• DC Output voltage
drops
If the voltage loses regulation
and drops to < 13.5V, the unit
is overloaded and is in current
limit. The load is trying to draw ≥
the current limit value
If the voltage drop is consider-
able with voltage < 2V, the load
side is seeing a short circuit and
short circuit current limited to
the current limit value is being
driven into the short circuit
Reduce the current drawn by the load to
less than the continuous rating.
Switch OFF the load. Remove the short
circuit on the load side.
GFCI outlet / GFCI break-
er supplying AC power
to the unit trips when the
unit is switched ON
Additional RF noise currents from
the unit that are ltered to Earth
Ground increase the net Leakage
Current on the GFCI outlet /
GFCI breaker to > 4 to 6mA
Switch OFF other SMPS devices operating
from the same GFCI outlet / GFCI breaker
to reduce the net leakage current to < 4mA
Move the unit to another GFCI outlet /
GFCI breaker that has lesser number of
SMPS load(s) or no SMPS load
Power the unit from normal, non GFCI
outlet or from an outlet not protected by
GFCI breaker