It is best to have it plugged up and unplug the power connector off the motherboard.
Do i need an antistatic mat to build a pc.
Just take the other necessary precautions.
If i handle a bare mainboard i use an esd mat too but when i just add components into an existing pc there is no point in using a mat.
Anti static mat esd mat with wrist strap and grounding cord auory silicone soldering mat heat resistant 932 f for phone computer laptop electronics repair assembly 15 8 x 11 8 gray 5 0 out of 5 stars 3.
Instead of using a wrist strap connect the chassis to earth ground roll up your sleeves to maintain contact with the chassis exposed metal.
Just plug the pc in an outlet and connect the wrist strap to the pc case.
Make sure you have one hand or your forearm touching some metal part of the case while working.
I am a field tech and have never carried around a mat or strap.
The wrist strap is not necessary as long as you and the computer are grounded to a common point.
That is why i always use a wrist strap and wear cotton clothing when working on hardware.
Since carbon is conductive if the mat is laid on top of conducting tables and floors static will travel through the mat into the table and dissipate at the floor into the ground.
Do i really need an anti static work mat.
Electrical outlets are normally the best ground for a mat in any building.