# Thread: VR and SMD capacitor soldering question

1. ## VR and SMD capacitor soldering question

Given the picture below for a vdroop mod on the asus p5n-e SLI, does it matter which end of the SMD capacitor I would solder the VR to?

Also, would I connect the wiper terminal or track terminal of the VR to ground?

Thanks.

2. You solder the VR to EACH side of it! Ergo you solderiton top.
I would use a wire to each side of it

3. so the wire would go to each side of the track terminal and the ground goto the wiper terminal? Like so in the diagram...

4. Originally Posted by jinsean
so the wire would go to each side of the track terminal and the ground goto the wiper terminal? Like so in the diagram...
NO Ground is Needed

Remember to mesure teh Variable resistor, You must be able to get 1000 Kohm and then down.

When VR has 3 "pins" normaly you use 1 in the middel and 1 in the side.

That gives you a span of 1000Kohm/1 Mohm

EDIT: But please make sure you unserstand what Im saying correct.

Because I have problems understanding you point

5. I think what you're saying makes sense.

VR zone has all diagrams like these. So I was assuming there might be a ground involved. And that I might only need to connect the VR to one end of the SMD cap only.

Link to VR zone mod page

edit: the picture below is NOT for the vdroop mod, it's for vcore I think, which I don't care for.

6. In a picture like #6 you would do exacly what I sayd, EXEPT only 1 at the Green spot and 1 at ground

7. Edit: I don't need to worry about ground. According to couppi, I just need the two connectors hehe. Silly me.

Also, how do I know which way I'm supposed to turn the dial of the VR for max / min resistance? Clock-wise? Counter-clockwise? Can I just hook it up directly to a DMM to figure it out?

I believe in general, I want to set the VR to MAX resistance then start lowering the resistance to increase voltage, right?

Do I need the motherboard to be plugged into the PSU and "on" to read the current vcore with a DMM? Or can I just use the DMM with the motherboard not powered on to check that stuff?

Sorry for the stupid questions, but I don't know too much about electronics.

8. Originally Posted by jinsean
Also, how do I know which way I'm supposed to turn the dial of the VR for max / min resistance? Clock-wise? Counter-clockwise? Can I just hook it up directly to a DMM to figure it out?

I believe in general, I want to set the VR to MAX resistance then start lowering the resistance to increase voltage, right?
Yup.
I assume you'll be using a multiturn POT (VR), just mark the leads you'll be useing (Sometimes they come with 4 or 5 leads...or even 6), and turn the VR so the resistance is at its highest between the 2 leads you'll be using.

Originally Posted by jinsean
Do I need the motherboard to be plugged into the PSU and "on" to read the current vcore with a DMM?
Yup.

Originally Posted by jinsean
Sorry for the stupid questions, but I don't know too much about electronics.
Stupid questions are the ones not being asked. So no need to be sorry about that.

It's better to be safe than sorry....so if you have any doubts...please ask, I know my explanation is right, but if you misunderstood my explanaition things may get ugly.

So don't hesitate to ask "dumb" questions when you're in doubt.

9. Use thin wire.

10. It seems my local radio shack only carries 22AWG hook up wire. When I connect the wire to the SMD cap, I'll try only using a few strands from the wire. Connecting to the VR should be easy.

Also, I need a 1mOHM VR, but the one at Radio shack is giant! I'd prefer to use a trimmer/preset, but they don't have a 1mOHM trimmer =/

Will have to find some clever way to mount a the giant VR onto the mobo or maybe i'll just use really long wires and mount it somewhere more concealed...

11. That's the wrong type. You need a multi-turn trimmer (minimum 15 turn). Individual wires from an 80 wire IDE cable works good.

12. Originally Posted by Praz
That's the wrong type. You need a multi-turn trimmer (minimum 15 turn). Individual wires from an 80 wire IDE cable works good.
Radio shack doesn't carry any other 1mohm trimmers or pots =/

Know of any other places that has a good selection?

13. Use 2 x 500 K 0hms resistors and set them in parallel.

14. Originally Posted by Nosfer@tu
Use 2 x 500 K 0hms resistors and set them in parallel.
It's better to put them in series

15. They make SMT 1 mega-ohm VR with trimmer screw to go down to 10 ohm. surface solder just like the one you are removing but higher with a small trimmer screw .

below is one style,other are available depending on space confinements

16. Originally Posted by KILLorBE
It's better to put them in series
haha Correct, My mistake.
Imeant put them next to each other and connect them in a serie.

Sry.

17. I know the info on soldering and v-modding is out there, but i wish one of our talented modders would make a sticky.

1. what types of resistors are best, with pics and links preferably.
2. what irons are best, show some budget ones and some nice ones.
3. what type of solder and sizes to use.
4. what sizes and types of wire to use.
5. show and explain good multi-meters and what we need in a mm.
6. explain what other items we will need to get before we start.
7. show some quick diagrams to explain the purpose of adding or lessening resistance across sample circuits.
8. give some tips, protecting from heat, preparing surface, preparing tips, cleaning etc.
9. show how to test the mod to check resistance.
10. things to check before you fire the rig back up..etc.

Like i said i know the info is out there but alot of it assumes we have all worked with electronics before and doesn't cover the bases.
a really good sticky could even become a sort of wiki with members adding info they feel is left out or updated with new ideas or methods.

i know i spent two hours practicing on old sound cards and etc before i tried my p5b-deluxe v-core mod and i still couldn't get it right and wound up removing it before i powered up the board.

18. Originally Posted by jimmyz
I know the info on soldering and v-modding is out there, but i wish one of our talented modders would make a sticky.

1. what types of resistors are best, with pics and links preferably.
2. what irons are best, show some budget ones and some nice ones.
3. what type of solder and sizes to use.
4. what sizes and types of wire to use.
5. show and explain good multi-meters and what we need in a mm.
6. explain what other items we will need to get before we start.
7. show some quick diagrams to explain the purpose of adding or lessening resistance across sample circuits.
8. give some tips, protecting from heat, preparing surface, preparing tips, cleaning etc.
9. show how to test the mod to check resistance.
10. things to check before you fire the rig back up..etc.

Like i said i know the info is out there but alot of it assumes we have all worked with electronics before and doesn't cover the bases.
a really good sticky could even become a sort of wiki with members adding info they feel is left out or updated with new ideas or methods.

i know i spent two hours practicing on old sound cards and etc before i tried my p5b-deluxe v-core mod and i still couldn't get it right and wound up removing it before i powered up the board.

I don't have time to do ever thing you want but resistors,not SMT have a color code

#1 no band +/- 20&#37; accuracy
silver band +/- 10%
gold band +/- 5%
red band +/- 2 %

#2 I may use a good iron that has accurate temperature control or use a Weller cordless iron since its cordless it's ESD safe just like the good ones.It control heat buy adding fuel with a dial,not as accurate but woks well for me.You can also get a cordless rechargeable iron.
Always protect from ESD. for super sensitive PC electronics use a ESD mat,wrist band & ground strap,monitor (checker) before you start

#3 solder size need to suite job

#4 wire needs to carry load,small solid wire I think is neater for some applications, as is hold it's bends not as flexible at heavy gages. Stranded is larger and has more resistance,but not to worry in short pieces.

#5 you need a true RMS mm with capacitance and dc millivolt,resistance ,k themp probe If your into phase a fluke 116 is a great starter,of course a scope meter is best. Big \$\$\$\$

#6 &7 buy a book and get a bread board and variable power supply. Some bread board come with the power supply. and some projects from radio shack,like building a quartz clock,radio, transmitter,,timer plus many more kits you learn all along. Or buy a master kit with all the needed components to build a projects even using a led as a poor mans mm.

#9 set meter to appropriate ohm scale ,usually the highest scale then come down to get a more accurate reading unless your meter auto ranges, some meters now auto-detect whether you are testing DC or AC

#10 you mod is done on the exact board and in the right place,unless your a electronic engineer and you can design and test mods. not for a beginner

#11 keep in mind voltage & amperage can kill you

#12 make a clean organized work area well lighted, start on the project I mentioned,not expensive mobo's you have a lot to learn and your not going to learn all the the ohms law and many more by a post here and there.

#13 It you job to either buy a book on basic electronics or get one from the library.Buying is recommended so you have a reference.possibly read a few from a library and find one you can @ your level understand first.Ask you radio shack dealer or electronics parts store,much of the simple stuff is resistor/capacitor controlled. buy some cheap 555 timers or 556 duel timer chips to solder dips, and build timer delay circuits.you need practice. much of this is just to prepare you and teach you the basics. Sure you may solder a wire from point a to point b with a VR pot or resistor in between but you still don't understand what you are doing. you need to learn electricity 101 then electronics 101. electrical engineering is different than electronic engineering.You need to understand electricity,all the laws and the way we measure watts,volts amps resistance,capacitance and on and on. don't count forums to teach you,but more too point you in the right direction.

Below is pictured a resistor color code identifier on one side & inductor color code on the other. I'm sure you noticed the color rings on NON SMT resistors.
This is were you must start at the beginning to learn the basics.Many here will help butt you need to understand a single question may take several pages or more to answer accurately. You must learn how to read and comprehend what you read .If not re-read till you do. Or take a course in school or at a vo-tec night school depending on you age.

pics are below This is where you must start with a good book and some easy projects to ultimatly understand Electronics. BASICS first. Other wise all you will learn is to solder conponets without understanding why. you have a long journey,but once you reach the destination,you will see its worth the trip. Good luck, hope this helps.