PSU Mod Questions

[BellaCroix]

I'm planning on completely rewiring my power supply (tired of extra wires hanging everywhere which are 2 feet two long for my case) but I've a few questions I was hoping one of you could help me with:

1: How do you discharge the capacitors? Is it possible? I'd rather not worry about electrocuting myself the first time I touch a soldiering iron to the board.

2: Is there some reason every power supply only puts 3 molex per wire? Lets say I wanted to put 5 connectors off a single strand? What would happen?

BTW: I'll probably be doing this on an Enermax PSU if it makes any difference.

Thanks in advance!

 

[StephenIsTheMan]

Why not just chop them of out side the PSU, with enough length left so you could reattach if needed, were there is only 12v. I wouldn't worry too much about the caps, just take the innerds out carefully and short every thing you can see with a screw driver while holding the plastic non conductive handle.


/ not responsble for you winning a darwin award.

 

[Tanis143]

To discharge the caps unplug your power supply cord from the electrical outlet and hit the power button on your computer, this will cause the PSU to discharge its caps thinking it has power, which it wont.

As far as the molex's are concerned, think of it this way. Why cant we just add power strips on top of power strips? Too much current running through a single set of wires. Granted, using a few y splitters ont he power leads never hurt, but you would not want to push it.

 

[BellaCroix]

Originally posted by StephenIsTheMan
/ not responsble for you winning a darwin award.

Now that's funny! I could be famous... I can see it now. "In an attempt to pimp out a computer case, A Cleveland man electrocuted himself on a computer's power supply after removing the 'no user servicable parts inside, do not open, severe electrocution danger' label. As a side note, the case is now for sale at [H]ardOCP"

The power suppy I currently have has sliced cabels after the wires leave the PSU, cut them at the molex then resoldered them. I was really looking more at cutting the ATX and 12v cables at the board (because I'm tired of trying to pry the square pins out of those connecters) and completely removing the AUX power connector which I have no use for.

Thanks for the idea Tanis143... that sounds like it may work... if I don't post for a couple weeks you know what happened. Heh.

 

[eternalspire]

Originally posted by Tanis143
To discharge the caps unplug your power supply cord from the electrical outlet and hit the power button on your computer, this will cause the PSU to discharge its caps thinking it has power, which it wont.

WHAT THE @##$%#$@# ARE YOU TALKING ABOUT???????

The power switch on an ATX power supply plugs into a motherboard which has no way of doing anything without the power supplied by the pluged in power supply. Don't tell people how to make electronics safe if you don't know what you are doing.

 

[Wixard]

About unpluging a psu and hitting the front panel switch:

Im not sure how much it reduces your chance of being electrocuted, but i have seen fans spin for seconds while doing that "trick" So it must draw some sort of power.

 

[ChingChang]

You can easily make a discharging tool with a screwdriver and some wire. Wrap a wire around the third prong (ground) of a computer power cord. Attach the other end of the wire to a screwdriver. Now you can discharge the capacitors with it

 

[Tanis143]

Originally posted by eternalspire
WHAT THE @##$%#$@# ARE YOU TALKING ABOUT???????

The power switch on an ATX power supply plugs into a motherboard which has no way of doing anything without the power supplied by the pluged in power supply. Don't tell people how to make electronics safe if you don't know what you are doing.

And dont correct people unless YOU know what you are talking about. How does the motherboard turn on the pc? Simple, the atx power on header goes to the atx powersupply connector, makes a connection between the green power on lead and a ground, causing the psu to power up. Now, you unplug the power cord from the psu, hit the power button on your case, the psu still has enough of a charge in the caps to try and turn on, using the charge in the caps first. If there is no power running to the psu, it discharges the caps.

If you think I am wrong, try it. You see the power light flicker on, the flicker off briefly. Also, another way to discharge the caps is to unplug the power cord and have a nic installed thats attached to a network. Because most motherboards support WOL it always has a trace current monitoring the nic. So, by unplugging the power cord, the trace current to the nic will drain the caps. Again, do not believe me watch the green led on the back of your nic after unplugging the psu, it will stay on for a few seconds then fade out.


And yes, I have tested this by applying this technique, then popping open a psu and testing the caps for a charge. WOW, guess what, no charge was found.

 

[FLECOM]

for the love of god do not discharge caps with a screwdriver or anything else... just unplug, hit your power button, then wait a few mins - like 5... you should be ok

powersupplies arnt like monitors that need huge amounts of electricity stored in a cap for the flyback transformer and such

they discharge easily and in realitively little time

 

[eternalspire]

That is what happens when I jump on here after writing a 5 page Hist paper. Sorry Tanis you got it right. The power button is not wired directly to the PS plug. It activates what is basically a latching relay. Guess I just thought the unpluged supply wouldn't supply the power to activate it.

 

[ChingChang]

Originally posted by FLECOM
for the love of god do not discharge caps with a screwdriver or anything else... just unplug, hit your power button, then wait a few mins - like 5... you should be ok

powersupplies arnt like monitors that need huge amounts of electricity stored in a cap for the flyback transformer and such

they discharge easily and in realitively little time

I know they aren't nearly as powerful as the energy stored in a monitor, but why can't you use the screwdriver? Will it damage the PSU?

 

[Tanis143]

Originally posted by eternalspire
That is what happens when I jump on here after writing a 5 page Hist paper. Sorry Tanis you got it right. The power button is not wired directly to the PS plug. It activates what is basically a latching relay. Guess I just thought the unpluged supply wouldn't supply the power to activate it.

Hey no problems, I've been there before

 

[Tanis143]

Originally posted by ChingChang
I know they aren't nearly as powerful as the energy stored in a monitor, but why can't you use the screwdriver? Will it damage the PSU?

Simply put a discharge with a screwdriver basically shorts out the cap, causing the stored charge to jump. Where it goes is anyones guess. It could trave up the screwdriver and shock you, or it could shock the PSU and blow out a component. You want to discharge the caps in a slow controlled manner to avoid any damage to yourself and/or electrical components. And even though the charge on the cap may be low, just remember, any shock that generates a visable spark is about 100 times more powerfull than a charge needed to destroy an electrical component. So, why risk it, especially when its easier AND safer to discharge the caps by the method both FLECOM and myself suggested?

 

[Bananadog]

sorry if i'm going to thread hijack here but i have a question regarding molex connectors. I've figured out how to remove the male ones in order to sleeve them, but in looking at the female connecter, i see how i have to remove it, but is there any way to remove it without paying 10 bucks for a removal tool, any one have any experience with this like to give a hand?

 

[ChingChang]

Originally posted by Tanis143
Simply put a discharge with a screwdriver basically shorts out the cap, causing the stored charge to jump. Where it goes is anyones guess. It could trave up the screwdriver and shock you, or it could shock the PSU and blow out a component. You want to discharge the caps in a slow controlled manner to avoid any damage to yourself and/or electrical components. And even though the charge on the cap may be low, just remember, any shock that generates a visable spark is about 100 times more powerfull than a charge needed to destroy an electrical component. So, why risk it, especially when its easier AND safer to discharge the caps by the method both FLECOM and myself suggested?

Well the screwdriver is grounded, so I doubt it would shock you... or it would be suicide doing it on a monitor.

I've never actually used the screwdriver method for a PSU. What I do is like you guys said hit the power button a few times, and then also leave it unplugged for a couple days just to be sure. Now I know not to use the screwdriver method, thanks.