Modding Get this when working with PSU?

Since I am scared to mod my PSU, I was looking for something to show me what to do, I found this, so I am wondering if it is worth it, or what else I should do?

 

what are you wanting to do with your PSU?

 

Personally I wouldn't bother with it while working on a psu, nothing overly sensitive to static in there.

Just unplug the psu and leave it overnight, if your worried about shocks, though it should be safe after half hour or so.

What do you want to do to it?

 

that wont save you from electric shock, just delicate components from the static charge of your body (eg. RAM) although i've never used one and not fried any memory yet but theres nothing in a PSU that will warrent the use of a wrist strap.

if you're scared of shock (hell, i am) leave your PSU unplugged for a while (hopefully somone will be able to give a more precise ammount of time) i usually leave it for a day or 2, and if your really worried you can discharge any big capacitors with a plastic handled screwdriver, although i've not myself ever done that, i've heard of people who have.

matt

edit: darkinferno beat me to it

 

I heard that if you un-plug the psu, and then press the power button on the PC, it's supposed to discharge the caps in the PSU. I wouldn't want to test this theory though, just in case it doesn't

 

The caps have bleed resistors across them, so they discharge themselves in a very short time.

 

I am looking to make it smaller and change the case, I saw a guide for it, but dont remember where it was... If anyone has a guide, that would be great!


Thanks for the advice!

 

That's right, u won't damage any sensitive electronics (there are none in a psu), instead the PSU may damage YOU. But that maybe a street legend. If u want to be absolutely sure, just make yourself a discharger which is, how simple can this get, a 1 Mohm resistor with two allligator clips.

Here's a worthwhile PSU mod idea (not new). Make it fanless by relocating the power transistors (the ones mounted on a large heatshink), and mount them directly on the case and use an external large heatsink that ventilates directly to the outside.

Of course u want to make sure the PSU ground and the case ground are the same, else I hope u got insurance

 

I was curious about discharge time myself, so I attached my multimeter to one of the 12 volt rails and killed power. A "good" no-name psu I had took 20 minutes to discharge into the mV range. A crappy no-name psu took about 5 minutes. So basically unplug it and it let it sit for a while.

The better test would to have attached the multimeter right to the caps, but I wasn't in a position to tear these supplies apart.

 

it discharges the caps most of the way, but it also depends on how much stuff u have connected.

 

In theory the PSU should try to provide standby power on VSB as long as it can; so if your computer is turned off but still uses standby power you can pull the main power plug and wait a minute. Many mobos have a LED on them that lights up if VSB is present. Anyone to confirm this with an experiment?

I disagree with the previous statements that there aren't any sensitive components in the PSU. The big transistors are MOSFETs and their punch through gate to source is at most 20V. Better make it a habit to ground yourself when you work around them, or at least choose a rainy day.

While modding you should also consider the impact on your mobo. A little drop of solder that shorts something in the feedback for the +5V circuit can easily make the 5V output a 20V output, which will fry your mobo.

 

I go by that as a rule of thumb, same with the turning on and letting the rest of the power discharge thing. I've done quite a bit of PSU work and never been shocked, but I'm relatively careful. I don't know of a good way to find out of my caps are still full, other than licking them which for obvious reasons is hardly the best way.

Don't unplug the PSU though, just turn it off using the big switch on the back. That way it remains grounded. Not when working in it of course, but for discharging. Of course if it doesn't have that switch then do unplug it.

 

If you're grounded then that's possibly the worse thing you could do when working on a PSU. If you're grounded the caps will tend to discharge into you if charged therefore frying your a*s!

 

I wouldnt worry about it too much, just make it a point not to lick a capacitor. If you're still afraid to mod your psu, then let it sit for a day before working on it. For the most part, there's nothing to worry about. Theres not enough potential voltage in there to kill you. only enough to make your arm go numb for about 10 minutes max, and thats a whole new fun adventure in itself! Mod away my friend.. mod away!

What do you plan on doing to your PSU anyhow?

 

Acrilic case, smaller box and maybe lights?

 

I have my hands in PSU's all the time, just have it running with a fan plugged in and unplug it from the wall outlet or from the psu itself your fan will run for a second or so and will drain the capacitors when the fan stops there's no danger you can touch anything
This is right after unscrewing the 4 corner screws, everything was still warm



And this is to show you i'm telling the thruth about working in psu's loll