Most standard computers can
take any standard Power Supply Unit with standard connectors. This means it
is fairly easy to replace a PSU using an other model number, providing the
size or the screw holes match.
Note that our
replacement Power Supply Units are not direct replacements. The brand, model
number, electric specifications and connectors may vary slightly from your
original PSU and we
cannot guarantee that they are 100% compatible with your hardware
specifications. They are only high quality alternative PSUs and they do the job with no problem
in most cases.
In rare cases you may encounter some issues and some slight adjustment may be
required to fit your computer (additional connector adaptors, etc...).
Should you have any query,
please do not hesitate to send us pictures of your PSU, PSU label,
connectors, rear of chassis, inside of PC, together with your original PSU
and PC model numbers. We usually provide a simple solution for most
issues described bellow.
Should you still need to return your item please request
an RMA Number and use this
Please see a list of
the questions you might have about a PSU purchased from us.
The PSU connectors are wrong,
too short or missing
The PSU wattage is wrong
The PSU voltage is wrong
The PSU fan position is wrong
The PSU current ratings are
The PSU is missing the monitor
The PSU model
number is correct but the specifications are wrong
The PSU size is wrong
The PSU does not fit
The PSU does not work at all or works
PSU connectors are wrong, too short or missing.
ATX connector (20, 24 or 20+4pin):
-Older boards require a 20pin
ATX connector and new boards require a 24pin connector, so most PSUs have a 20+4pin to
fit all boards. Check if the new PSU has
this additional 4pin square connector (with yellow, orange, red and black
wires) often labelled “24”. It needs to be attached to the side of the 20pin
connector and there is only one way to plug it in. Not to be mistaken for
the square 4pin P4 connector with yellow and black wires. This similar
looking connector has a different shape and will not fit near the 20pin
Some PSUs have a 24pin or a
20pin connector only and may require an adaptor (20 to 24pin or 24 to 20pin). Please ask for a suitable adaptor
Note that It is OK to plug a
24pin PSU connector into
a 20pin Motherboard socket, leaving the extra 4pin hanging on the side
(providing there is no components obstructing the insertion on the
When a 20pin connector is paired
with an extra 4pin connector, its clip is wide and off centre.
When a 20pin connector is NOT
paired with an extra 4pin connector, its clip is small and in the
24pin connector plugged into a 20pin motherboard socket.
In the second picture, components
are in the way, so a 20 to 24pin adaptor is required.
-Some odd PSUs have a
special main connector (NAS boxes...). It may physically fit the motherboard but
if the wire colours are different, damage may result. Please check your
connector pinout and ask for availability.
Standard ATX 24pin connector pinout
There are 2 types of similar
looking 8pin connectors on a PSU. Their pinout is slightly different:
-8pin EPS 12Volt connector for the motherboard.
Usually on high end PSU. Also available as optional adaptors (4pin-to-8pin
EPS or Molex-to-8pin EPS adaptors).
-8pin (or 6+2pin) PCI-Express connector, connected
to the motherboard or to the PCI-E cards. Usually on high end PSU. Also
available as optional adaptors (6pin-to-8pin PCI-E or Molex-to-8pin PCI-E
adaptors). Note that a beveled second pin goes to the PCI-E cards and a
square pin goes to the motherboard.
AT P8 & P9 Connectors (on older type of PSUs)
-The old type of AT PSU for
legacy AT systems has been discontinued. Our replacement PSU comes with P8 &
P9 connectors with standard colour wires. However, some AT PSU (such as the SFI-300G) may have wires with different colours. This is fine since
their currents are the same. Therefore, our AT PSUs can safely replace your
AT PSU even if some wire colours are different.
SPI-300G AT PSU Wire colours
Standard AT PSU wire colours
-All our PSUs come with
standard connectors, however, the types and numbers of connectors may vary
slightly depending on PSU model numbers and versions. If you requires
additional connectors, we can supply a wide range of adaptors or extensions to meet your needs.
-Some SATA connectors in slim
chassis may be to long to fit due to a lack of room behind the drives. Ask
for a "Right Angled SATA Adaptor".
Right Angled SATA connector
Standard SATA connector
-Should you a require a non
standard connector, it may possible to cut it off your old PSU and DIY
reconnect it (at your own risk) to the new PSU. In order to keep the new PSU intact
and its warranty valid, we recommend to work on a cable extension rather
than cutting the PSU cables. Contact us to see if we can help.
2 The PSU
Wattage (power output) is wrong.
-Most of our power supplies deliver 250 to 350watt which is usually
sufficient for a standard home or office PC. A hungry PC such as a gaming
machine or industrial server may require a higher 400 to 500W PSU. A wattage
higher than your original is fine and will not damage your PC. The PC only draws the amount of
power it requires. In fact, the more power the better. It allows a more
stable system and more future upgrade possibilities. The wattage is
indicated in the PSU model number and on the label.
300Watt output PSU
300W output PSU (276+24)
3 The PSU
Voltage is wrong.
PSUs are Auto Range (Full Range) and switch automatically between 110 and
230volts. Some PSUs have a small red volt switch that needs to be set manually to
your country's voltage before connecting the PSU to the Mains. Some of our PSU are only set to 230Volts and are therefore not
suitable for 110volt countries. Please check the "AC Input" information on
the PSU label and check if there is a red switch near the power socket.
Suitable for 110 & 230V countries (No volt switch. The
PSU is Auto Range. The voltage is changed automatic)
Suitable for 230V countries only (No red volt switch,
The PSU is set to 230V only)
Suitable for 110 & 230V countries (With red volt
switch. The voltage is changed manually)
4 The PSU fan
position is wrong.
-The position of the fan does not
usually affect the efficiency of the cooling. The hot air is sucked
out from the inside of the chassis and PSU, to the outside.
rare cases a PSU with a fan situated at the top may not fit a small or 2U
chassis due to the lack of room for ventilation. Most new PSUs have a
quieter and more efficient 120mm fan on top. The fan usually faces the board
/ CPU once the PSU is installed. Ask for a PSU with an 80mm fan at
the front if required.
Check this guide.
PSUs with different fan configurations. The air flow
remains the same. A 120mm fan tends to be more efficient and more quiet.
The 1U PSU on left has the fan at the rear (near the
cables) and the 1U PSU on the right has the fan at the front (near the power
The air flow remains the same. The arrows marked on the fans show the
air flow and rotation direction.
The air usually comes out from the side where the
5 The PSU
current ratings are wrong.
PSUs have slightly different current rating shown on the PSU label. This is
usually not a problem, unless you have a very specific rating requirements
for a special motherboard.
-Latest PSUs do not have the obsolete -5Volt white wire
in pin 20 (left empty).
Should you require this -5V rail, used for older boards with
ISA slots, order a suitable PSU.
Older PSU with -5Volt Rail (white wire in pin 20)
New PSU with no white wire
6 The PSU is
missing the monitor outlet.
-Some older PSUs, especially AT PSUs, used to have a Monitor Outlet next to
the Mains Power Inlet. This was for the monitor or other devices. Latest PSUs do not have
this Power Outlet. The monitor outlet provides the same voltage as the one
from the mains, so you can get round this by using a standard PC power cord to power
the monitor. A twin power cord can also be used to minimise cabling. If you
really need a monitor outlet, order one of our rare PSU with a monitor
Check this guide.
Monitor outlet on older type of PSUs.
The monitor or other devices can be plugged directly
7 The PSU model number is correct but the
specifications are wrong.
-In rare cases two PSUs with
identical model number and size have different specifications or connectors. This is because a standard PSU
modified by the manufacturer to fit a non standard PC and the model number
was not changed. This can lead to confusion when ordering a replacement for
a non standard PSU, so please check your
requirement or contact us for assistance as we cannot be held responsible
for errors resulting from such confusion.
-If available, we can provide parts to go with our PSUs in order to match
your requirements, however we
cannot refund the cost of parts purchased from other suppliers (Connectors,
Adaptors, Extension cables...).
These two PSUs have the same model number FSP350-701UJ
and look identical however their connectors are different. The non standard
PSU on the left has 2 special connectors for QNAP NAS boxes and the standard
PSU on the right has all the usual ATX connectors (Molex, SATA, Floppy,
8 The PSU size
PSU sometimes have a different size or shape from the original but most of the
screw holes should match your chassis. Some PSUs may be supplied with a metal
adaptor bracket in order to fit your chassis, but this would be clearly
indicated on the product page.
Our PSU on the left replaces the two discontinued PSU
on the right. The screw holes are the same.
Our PSU on the left replaces the discontinued PSU on
the right. A metal adaptor bracket is supplied in order to match the screw
9 The PSU does not fit.
-Most screw holes on our PSUs match the chassis and are sufficient to hold it
in place, however, some screw holes may be missing or our fitting bracket
may not fit perfectly.
the shape of the PSU cut out (PSU hole) on the chassis does not allow the
installation of a PSU due to the position of the cooling fan, the On/Off
switch or the power inlet. Please check compatibility, ask for the switch to be removed or ask for an alternative
Check this guide.
On the right, this is an example of a PSU which had the On/Off
switch removed in order to fit a particular PC with no holes for the switch.
These two computers can only take a specific type of
PSU due to the shape of the cut out on the chassis.
-Some PSUs have an indent and
hold on a hook in the chassis. If our replacement PSU does not have the
indent, it may be necessary to flatten the hook in order to allow the PSU to
PSU with indent
PSU with NO indent
10 The PSU does
not work at all or works intermittently.
-Our high quality PSUs are very reliable and are tested
prior dispatch so they are unlikely to arrive faulty, unless they have
sustained some damage during transit. We suggest
you to retest the PSU by making a bridge with a paper clip between the Green
and any Black wire before connecting the PSU to the mains.
See bellow how or
If the fan does not spin, the
PSU may be dead, please
open a return case and we will replace or refund it.
If the fan spins, the PSU is
likely to be working and there
may be an other issue with your PC (faulty motherboard etc...), please open
a return case and we will refund it.
-Some PSUs may appear to work intermittently. This is usually not due to a lack of power (please
compare the wattage with your original PSU's). It is often due to an unexplained electrical
incompatibility issue. This issue as been reported with some HP Pavilion
computers for which a more performant PSU has solved the problem.
This is how to test an ATX PSU
Disclaimer of Liability:
-The information contained in our Power
Supply compatibility lists is accurate and reliable to the best of
our knowledge, however, we do not assume any liability whatsoever for the
accuracy and completeness of the list.
-We cannot be held responsible for any
incompatibility or safety issue, damage, injury or loss of any kind related
to the use of our products.
-It is the responsibility of the buyer to
install and use our items in a safe and suitable manner and we cannot be
held responsible for any misuse of our products.
-Anyone who is not competent to carry out
installation of our products should seek professional assistance.