Seasonic GM-750 750W 80 Plus Gold Semi-Modular Power Supply Unit Installation Guide

: June 11, 2024
: Seasonic

Table of Contents

WARNING! IMPORTANT SAFETY INFORMATION
Remove your old PSU (power supply unit)
Test your Seasonic PSU before installation
Position your PSU
Install your Seasonic PSU
- Motherboard Cable
CUSTOMER SERVICE
References
Read User Manual Online (PDF format)
Download This Manual (PDF format)

Seasonic GM-750 750W 80 Plus Gold Semi-Modular Power Supply Unit

WARNING! IMPORTANT SAFETY INFORMATION

NEVER, under any circumstances, open the power supply unit. High voltage inside. WARRANTY IS VOID once the cover is removed.
DO NOT insert any object into the fan grill or the ventilation area of the power supply unit.
DO NOT place any object in front of the fan or the ventilation area of the power supply unit that may obstruct or restrict airflow.
USE ONLY the Seasonic modular cables provided with the power supply unit.
Keep the power supply unit in a dry environment, away from humidity.
The power supply unit is for integration into a computer system and not intended for external or outdoor usage.

Warning!

This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.

Product: Switching Power Supply
Model name: Please refer to the rating label on the product.
Contact: www.seasonic.com/contact-us

Remove your old PSU (power supply unit)

Disconnect your AC power cord from the wall socket and the back of the power supply.
Disconnect all DC cable connectors.
Remove all 4 mounting screws.
Remove your old PSU.

Test your Seasonic PSU before installation

Plug the AC power cord into the PSU.
Make sure that the AC power is coming directly from the wall outlet.

It is recommended to use a high quality surge protector to protect the PSU and the system.
Connect both the 18-pin and 10-pin connectors of the motherboard cable to the PSU.
If your power supply features a fan control switch, set it to “Normal” Mode*.

In Hybrid or Fanless Mode (S³FC) the fan will not turn.
1. If you have a Power Supply Tester, attach it to the 24-pin motherboard connector. There is a notch on the Tester that helps to make a perfect fit with the 24-pin connector.
  If you do not have a power supply tester, refer to the paper clip method described below.
2. (Optional) For testing a Fanless PSU or a PSU without the fan control switch, attach an external fan or LED light using a Molex cable to the PSU.
3. Turn on the power supply by setting the I/O switch to the “I” (ON) position.
  If the power supply fan starts spinning (or the externally attached LED light turns on), then your PSU is working.

Paper clip method

Use a paper clip or a piece of wire to create a short circuit on the 24-pin motherboard connector by connecting the pins shown on the illustration.

The drawings illustrate a fully modular PSU with a fan control switch and a Power Supply Tester; the features and accessories of your PSU might be different.

Position your PSU

Bottom of the case
The fan control setting determines the optimal PSU placement.

In “Hybrid” mode
Seasonic recommends to install your PSU with ventilation top cover facing UPWARD, towards the direction of the motherboard. This will ensure natural heat dissipation.
Fanless PSU
The PSU must be mounted into the computer case with the ventilation top cover facing UPWARD.

In “Normal” mode
Although the direction of mounting is optional, it is not recommended to install the PSU with the ventilation top cover facing downward if there are no ventilation holes on the bottom of the case. There should always be enough clearance left between the PSU and the bottom case panel.
Flat Desktop-, SFX- or ITX systems

In general, it is recommended to mount the PSU with the ventilation top cover facing the motherboard. Due to the different varieties of case layouts, however, please also consult the case manufacturer’s instruction manual for more information.

Top of the case

Seasonic recommends the PSU to be mounted with its ventilation top cover facing DOWNWARD.
Position your PSU
Mount the power supply with the ventilation top cover facing UPWARD only if there is enough space (at least 5 cm / 2 inches) available between the PSU ventilation top cover and the metal plate of the case, and only if the case has a ventilation panel on top.

Install your Seasonic PSU

Secure all 4 mounting screws.
Make sure the PSU power switch is in the “O” (OFF) position.
Select the fan control type if your PSU has this option.
Note: First power OFF the PSU before changing the fan control to take effect.
Connect all the necessary system DC cables (Motherboard, CPU, VGA, HDD, Optical Drivers, etc). The connectors should click to lock in.
ATTENTION! Use only cables provided by Seasonic! Should you require additional cables, please contact Seasonic.

Motherboard Cable

Please make sure both connectors on the power supply side are properly connected.
Motherboard Cable

CPU and PCIe Cables (8-pin connectors)
Peripheral Cables (6-pin connectors)
ATX 3.0 Compatible 12VHPWR Cable (16-pin connector)

Note: The power supply drawings are for illustration purposes only, your actual model might look different.

High powered graphics cards are usually outfitted with two or three PCIe power connector slots. Seasonic prefers the use of two or three separate PCIe cables to connect these cards to your power supply.

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