Should I hook up an anti-static wristband to the case or to a plugged in but turned off PSU?

[agentpenguin]

I've heard both and I'm not sure if one is better than the other or if it just doesn't matter.

 

[akio123008]

4 minutes ago, agentpenguin said:

I've heard both and I'm not sure if one is better than the other or if it just doesn't matter.

 

In an assembled computer, the PSU is attached to the case, therefore it's the same. 

 

In the event that you're dealing with an empty computer case with no power supply and no other ground connections, a plugged in PSU would be better.

 

Also the "but turned off" part is irrelevant for ESD grounding, that's just there to make sure the computer is off when you work on it.

[emosun]

You just have to touch anything metal thats grounded every now and then. Antistatic wrist bands are a good way to ensure you are grounded constantly which is good for insurance reasons but simply just touching something like a radiator also works fine.

[agentpenguin]

1 minute ago, akio123008 said:

In an assembled computer, the PSU is attached to the case, therefore it's the same. 

 

In the event that you're dealing with an empty computer case with no power supply and no other ground connections, a plugged in PSU would be better.

Ok thank you

[emosun]

Or you can touch anything that has a ground plug and is metal such as a microwave

[mariushm]

The idea is to have a continuous wire all the way from your hand to the earthing contacts in an outlet, so any static electricity gets discharged into ground.

 

So plug the power supply into an outlet, then attach your strap clip to any exposed metal on the power supply - the exposed metal is earthed in all power supplies, so as consequence, your strap will be earthed as well.

It doesn't matter if the power supply is turned on or off, the earthing/grounding wire is always connected.

 

If the power supply is screwed to the case, you're screwing the power supply using metal screws, so the whole metal of the case becomes grounded, because it touches the metal of the power supply and even if the power supply is fully painted (with pain that can be insulator), there's still a connection through the threads of the screws (there's no paint in the threads in the screw holes)

So, you can attach your strap to the exposed metal of the case, in the back (usually there's holes for fans, so you can easily clip there). Remember the reasoning, because you may make a mistake and put the clip somewhere in the front, where the metal may be inserted in a plastic frame or somehow not connected to the overall exterior of the case, where the power supply is screwed to.

 

The anti-static wrist wrap is basically a metal band that touches your skin and a resistor to limit the current... that's all, nothing fancy or special.