Watch the procedure on YouTube (3.5-inch)Power supply unit replacementFollow instructions in this section to remove and install a power supply unit.• “Remove a power supply unit” on page 170• “Install a power supply unit” on page 172Safety precautionsThe section lists safety precautions that apply to AC and DC power supply units respectively. Understandand apply the safety precautions before removing or installing a power supply unit.Safety precautions for AC power suppliesThe following tips describe the information that you must consider when you replace an AC power supply.S035CAUTION:Never remove the cover on a power supply or any part that has this label attached. Hazardous voltage, current,and energy levels are present inside any component that has this label attached. There are no serviceable partsinside these components. If you suspect a problem with one of these parts, contact a service technician.S002CAUTION:The power-control button on the device and the power switch on the power supply do not turn off the electricalcurrent supplied to the device. The device also might have more than one power cord. To remove all electricalcurrent from the device, ensure that all power cords are disconnected from the power source.168 ThinkSystem SR665 V3 User Guide