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PSU Modding Guide - Easy Way to Increase Your Voltage

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computerpro3

Member
Joined
Nov 1, 2003
PSU Mod Guide: How to adjust you voltage lines (and list of psu's with internal pots)

THIS GUIDE WAS WRITTEN FOR ANTECS, BUT SHOULD WORK ON ANY PSU WITH SENSE LINES (read below to find out what those are)

I encourage you to spread this guide around any forum you want, just please make sure to give me credit.

NOTE: I am not responsible for any damage or harm to your computer or yourself from attempt of this volt mod. Do it at your own risk. By reading about and/or attempting this mod, you acknowledge this and agree to it.

Equipment needed:


Soldering iron (15 watt preferred, $8 Radio Shack)
68Ohm fixed resistor ($1 Radio Shack)
33Ohm fixed resistor ($1 Radio Shack)
10Ohm fixed resistor ($1 Radio Shack)
1k Variable Resistor (aka potentiometer, $2.50 Radio Shack)
2x 10k Variable Resistor ($2.50 each, Radio Shack)
single strand electric wire (multiple strand works, just more difficult due to fraying etc., price may vary)
small flathead screwdriver for turning the VR knob
scissors/wire cutter
paper clip
Digital MULTIMETER - MUST HAVE ($20 Radio Shack)
wire stripper
Rosin Core Solder - DO NOT USE SILVER CORE SOLDER


Hi Everyone!
This guide will help those of you who have Antec power supplies that have low lines, or if you just want to raise them period. It is a great, easy mod, and if you follow the instructions properly, it will yield great results. The goal of this mod is to locate the atx sense lines for the 3 rails (or 2 if you have a cheaper supply), cut them, reconnect them with a fixed resistor in the middle, solder a wire from one side of the fixed resistor to the pot, and then ground the pot. That will allow you to change the voltage rails to your heart's content. Now that was probably a little confusing, so I suggest reading the rest of the guide before attempting this ;). Good luck and good modding!


Stage One


First, remove the power supply from the machine. This is a must, for obvious reasons. Bring it to a well lighted area with all of your tools layed out before you. Plug in the soldering iron in to allow it sufficient warming time while we plan the mod (warning, don't touch it to see how hot it is ;))
Now look at your atx connector. Here is a schematic of it.

pinout.JPG



Look at pin 11, the one that is in the upper left corner of the diagram. It reads +3.3vdc. This is the 3.3v line. Now there are two wires going in to this connector, one fat, one skinny. They should be orange. The thin line is the sense line, which is the one we want. Now locate the other two sense lines. The 12v sense line should be yellow, and located in pin 10 in the lower right hand corner of the diagram. The 5v sense line is directly above that in the upper right corner. Remember, DO NOT cut the THICK line, we want the THIN line. Decide how far up you want to cut the sense lines, whatever is most convenient for you. I recommend cutting them as close to the psu casing as possible, as to be able to mount the VRs when we are done on the psu casing for easy access. Let's tackle the 3.3v line first. Go ahead and cut the 3.3v sense line, the orange one originating from pin 11. Take the wire stripper and strip about 1/2 inch to 3/4 inch from the end of each cut wire.

Now, for the 3.3v line, you need to get the 10Ohm fixed resistor and the 1k Variable Resistor. Take the soldering iron and some solder and put a drop of solder on each end of the fixed 10ohm resistor. This is called tinning it; it makes soldering two wires together much easier as all you have to do is heat the drop of solder already applied to the wire and it will melt and bond the wires together. Next also tin the cut 3.3v sense wires. Now, on a flat surface, lay one end of the wire and the 10ohm fixed resistor together and solder them together. Once they are cool (give it about 5 seconds) solder the other end to the other cut wire.

PROGRESS CHECK

So far, you should have located the 3.3v sense line, cut it, and reconnected it with the fixed 10ohm resistor in the middle.

Stage Two

If you made it this far, good job. Next, find your 1k VR and grab your multimeter. Set the multimeter to measure ohms (the omega symbol) and set the VR to it's maximum resistance, which in this case is around 1k. All you have to adjust it is take your small flathead screwdriver and rotate the knob on the VR while watching the corresponding numbers on the multimeter. Don't worry if it is like 978 or something, as long as its in the general ballpark you're okay.

With that done, tin the middle leg and the leg closest to the knob with solder. Take some of your single strand wire (make sure you have enough to reach from the fixed resistor, which is where you will be soldering it to, to where you plan on mounting the VR!), strip the ends, tin the ends, and solder it to the front leg of the VR. Solder the other end of the wire to one of the legs on the variable resistor. Now choose any black wire on your power supply and strip a section of it WITHOUT CUTTING IT. Strip about a 1-2 inch portion, or large enough for you to ground your wires to. Now solder another single strand wire on to the middle leg of the VR and solder the other end to the stripped black wire (the ground). Your 3.3v mod is completed. It should look like this:

3.3v%20Mod.JPG


After you have done this, you have completed the 3.3v mod. Now comes the scary part, seeing if it works. Grab the power supply and bring it over to a wall socket. Before you plug it in, take a look at the atx power connector. Refer to the ATX pinout diagram, the first image of this guide. Find the pin PS_ON. The wire going into this should be green, just to be sure you have the right pin. Take a paper clip, straighten it out, and bend it in a U shape. Stick one end in the PS_ON pin socket and the other end in any black wire's pin sockt (you are grounding it again). This allows the power supply to start without a motherboard. Do not start it yet, though. Take your digital multimeter and stick one end (usually the red one) in pin 11 on the large ATX connector, the same one that has the two wires (sense and 3.3v line). Set your multimeter back to reading voltages. Now go ahead, plug it in and power it up. Watch your reading on the multimeter. It should be close to 3.3. Now take your VR, and turn the knob on it 1/2 turn at a time. The reading should begin to climb. I suggest stopping at 3.5 or 3.6v, that should be fairly safe and allow you all the voltage you need. I keep mine at 3.5. If the voltage reading doesn't move, turn the VR knob the other way. If the psu fails to start, don't fear (well, maybe a little bit) as the Antec TruPower series has excellent overvoltage protection. This usually means that you have the VR set with too little resistance. Crank up the resistance to the VR's max (eg: close to 1k for a 1k VR) and it should start. If it still doesn't start, ensure nothing is shorting out or touching. Ensure you don't have a cold joint, and that it is grounded properly. IF all else fails, remove the mod and solder the sense line back together. IF your psu is still alive, that will fix it. Alas, if you solder back together the sense line and it still doesn't start, I suggest you invest in a Pc Power and Cooling 510 Deluxe Turbocool power supply. No need for mods on that beast.

Now for the other two. They are EXACTLY the same, NOTHING is different except YOU MUST USE DIFFERENT VALUE RESISTORS. For the 5v mod, you must use a 33ohm fixed resistor and a 10k variable resistor. For the 12v mod, you must use a 68 ohm fixed resistor and another 10k variable resistor. Here are schematics of how the other two mods should look.

5v%20mod.JPG



12v%20mod.JPG







After you complete each mod, go back and use the method I described for finding your voltage. When you have all of the mods done, I strongly suggest using hot glue or crazy glue to mount your VRs somewhere easily accessible. I have mine mounted on my psu so all I have to do is open the side of the case and I can adjust them easily.

Vertigo Acid added:
It's a great idea to set the voltage when nothing to connected to make sure that everything is working and that the voltage is within safety windows. However, you also need to adjust it again, while the computer is underload. Regulation of the rails can and usually will be off when jump-starting a PSU with no load attached.

He's right, definetley do this.

Hope this guide helps some of you! Feel free to pm me with any questions!

-Computerpro3 out


ADDED ON 6-15-04

I will begin compiling a list of power supplies that have internal pots as a resource for anyone that does not want to mod their pc's. If anyone has pics of the pots, or knows psu's that have them, pm me and I will add them to the guide.

Thermaltake Butterfly 420w psu (hidden)
DCP02074-11.JPG

DCP02077-11.JPG


Fortron 530w
Here are some pics:
fortron%20530.jpg

untitled.jpg

untitled1.jpg


Pc Power and Cooling 510 Deluxe
super easy. They drill holes in the psu casing so all you have to do is stick a screwdriver in there. No pics needed.

antec pp403x and pp413x
Here are instruction on how to find + use the pots:

Originally posted by Buckaroo Bonzai on amdforums said:
The one closest to the fan is the 5v. You turn it clockwise to raise the voltage. The other pot is located underneath the wire bundle near the back of the psu. That is the 3.3v and you turn it counterclockwise to raise the voltage. Neither of these need much of a tweak at all! Like maybe 1/10 or less of a turn. Also, the caps in psu can store enough energy to kill you even when it's unplugged (although highly unlikely).

Channel Well CWT-420ATX12 (aka Antec pp412x)
No info on where yet but I would assume that they are in the same spot as the pp413x above.

Channel Well CWT-420ATX (aka Antec pp403x)
No info on where yet but I would assume that they are in the same spot as the pp413x above.

Allied 450w

Stevil said:
The potentiometer closest the heatsinks is the 3.3v adjust, the one farthest is the 5v and 12v adjust.
allied450.jpg


Pc Power and Cooling 510 (non deluxe)
Here's the ones for the pcp&C 510 non deluxe. The deluxe has holes drilled in it so you don't need pics.

turbocool1.jpg

turbocool2.jpg


OCZ Powerstream Series
They're on the back, also super easy.

OCZ%20Powerstream1.jpg



Credit is due to:
Xtremesystems.org for developing this mod and checking over my guide
Glock19owner for info on the Thermaltake psu.
felix88 for getting me those pics of the fortron
dss64662 for info on the pp403x and pp413x
Oklahoma Wolf for the info on the CWT models
Stevil for the Allied 450w info
 
Last edited:
OP
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computerpro3

Member
Joined
Nov 1, 2003
Thanks! I noticed a lot of people having low voltage lines around the forums. At xtremesystems.org/forums, where the mod was invented, i noticed how hard to follow the thead had become and decided to make an easy to read guide. The mods are not hard at all; the hardest part was figuring out what to do. I hope this helps!
 

rogerdugans

Linux challenged Senior, not that it stops me...
Joined
Dec 28, 2001
Location
Corner of No and Where
I have one or two power supplies that could use this mod.....;)

I may have to whip out the soldering iron this weekend and give it a shot.
 
OP
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computerpro3

Member
Joined
Nov 1, 2003
Hello everyone,

I am REALLY sorry I was not able to respond lately. I was locked out of my account for some reason. My password DID NOT work and it wouldn't email me the email with a new one when I clicked forgot password. It finally emailed me tonight and I reset it. The pics are gone because I re did my webpage which they are hosted on. They will be back up momentarily.

I will also add a small section of Thermaltake 420watt psu's hidden pots later.

Thank you for all the great comments and praise.
 
OP
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computerpro3

Member
Joined
Nov 1, 2003
bump...

Began making a list with pics of psu's that include internal pots as a refrence for people that dont want to mod their psu's and are in the market for one.
 
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NiTrO bOiE

Member
Joined
Dec 15, 2002
Location
Charlotte, NC
I did this mod to my true power last night (only the 12v rail because I only had 1 VR). My question is, why are fixed resistors needed? I did my mod with just a 10k VR and it worked fine. If there's something wrong with doing it that way, tell me before I damage my PSU.
 
OP
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computerpro3

Member
Joined
Nov 1, 2003
bump....added a lotta new pics and psu's with internal pots to the list. Anyone else know of any psu's with adjustable pots? TTGI will be up shortly, just waiting for someone to email me the pics.
 

RideZ

New Member
Joined
Apr 17, 2017
no, I can't see the pics either,

I know its a really old post but looks like great info
 

Alaric

New Member
Joined
Dec 4, 2011
Location
Satan's Colon, US
no, I can't see the pics either,

I know its a really old post but looks like great info

Considering the relative cost of a good quality power supply today, I would toss a PSU that was so far out of spec I had to do that to it. For less than 5% of my rig's cost I got a top tier, bulletproof PSU and don't have to worry about ripple, noise, or low voltage. And a 7 year warranty.
While I would be comfortable performing those mods, the big caps in a PSU can do serious, sometimes permanent, damage to a person. I don't see the value in it anymore.