# Check your Pot !



## greco (Jul 15, 2007)

I have been repairing the electronics in guitar for a friend recently. It was working OK but seemed to have "garbled" sound and was bit intermittent. 

I decided to check my work for cold solder joints, etc. as I had almost rewired the entire guitar. 

Then the guitar quit totally.

I checked and rechecked and rechecked again. Continuity was fine. 

I then decided to strip the connections off of the volume pot and test it...bingo...the pot was shot. It had been worked on before I got it and I suspect that it was a bit pre-cooked and I was just finishing the cooking. I thought that CTS pots could handle a lot...but I pushed this one over the edge.

Just a reminder to save yourself a lot of time and frustration by checking the pot(s) on your meter.

Cheers

Dave


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## mhammer (Nov 30, 2007)

Pots can often be rehabilitated. One thing I've often found that can bring a pot back to life is to pry the tabs up (not too much) of the back cover, and remove it. While the back is off, you can clean the crap off the resistive strip with a Q-tip, and apply some contact cleaner once the gunk is off. Then, with your needle nose pliers, gently pinch the rivets that hold the solder lugs onto the resistive strip. Very often, they can get loose over time and stop making contact. A little pinch to stabilize them can be all you need. Than put that cover back on the pot and pinch the tabs back in place.


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## epis (Feb 25, 2012)

mhammer said:


> Pots can often be rehabilitated. One thing I've often found that can bring a pot back to life is to pry the tabs up (not too much) of the back cover, and remove it. While the back is off, you can clean the crap off the resistive strip with a Q-tip, and apply some contact cleaner once the gunk is off. Then, with your needle nose pliers, gently pinch the rivets that hold the solder lugs onto the resistive strip. Very often, they can get loose over time and stop making contact. A little pinch to stabilize them can be all you need. Than put that cover back on the pot and pinch the tabs back in place.


,
I do agree 100% with Mark.Most of old pots can be fixed this way.Just to add, when you are there clean pot's wiper, most often it's made of brass or silver coated brass witch oxidizes (becomes black in color) trough the years. I do not use contact cleaner, for degreasing I use rubbing alcohol, after that a piece of paper (cardboard grade - rough surface) works great and doesn't make a damage to surface of the wiper ring.At the and I do apply some Gunk's liquid wrench spray, it's safe on plastic and it has good dielectric properties, and it's not expensive.


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## PickALick (Aug 4, 2012)

*opens baggie*
*sniffsniff*

Yeah, it's fine man, but thanks.  



Ok, all joking aside, do you guys have any good links that explain the process please? I want to learn more about the electronic side of things this time around. I eventually want to be able to be able to wire pickups (which I found out last night isn't as hard as I thought ... and not as expensive either), diagnose problems as greco did and all of that.

I can search my own stuff, that's fine. Just figured i'd ask if anyone had something handy or learned from something they now consider good reference material.

Thanks!


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## greco (Jul 15, 2007)

PickALick said:


> *opens baggie*
> *sniffsniff*
> 
> Yeah, it's fine man, but thanks.


I feel much better now, knowing that this thread served a dual and humanitarian purpose.

_____________________________________________________________


I don't know of any one specific book or link to a tutorial and/or YouTube video, but there are many if you just start searching.

The first thing, IMHO, is to get the basic tools and practice/develop your soldering skills. Again, there are many tutorials about soldering. 

Cheers

Dave


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## RIFF WRATH (Jan 22, 2007)

thanks fornot "naming names".........lol...............cheers, Gerry


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## greco (Jul 15, 2007)

RIFF WRATH said:


> thanks fornot "naming names".........lol...............cheers, Gerry


I would never tell anyone about your preferences when it comes to herbal medication.

Cheers

Dave


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## mhammer (Nov 30, 2007)

You will never regret joining or consulting the diystompbox forum or the music electronics forum.

While it can be hard to get, and can be pricey, I'm a huge fan of this stuff for restoring pots: Untitled Document


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## Electraglide (Jan 24, 2010)

Yup, check 'cause you don't wanna be making soup.

Anyway, I suppose that the same process for cleaning the pot can be used to rebuild it, if that's possible. I've got a volume pot on an old hollow body that just turns. If you play with it for a while it will work.


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## PickALick (Aug 4, 2012)

greco said:


> I feel much better now, knowing that this thread served a dual and humanitarian purpose.
> 
> _____________________________________________________________
> 
> ...


Well i've got a Chinese Bullet here that's waiting a few mods i'm dying to try, so I guess it's "sink or swim" time. What's the worst that'll happen - it won't work, right?!?!?!?

:/ RIGHT????????????????????

*pictures Marty from Back to the Future flying from the 72" speaker*  

I want to run it with only the neck and bridge pups, and a "global/overall" single volume and single tone. Will hit up Seymore Duncan site for schematic. Seems pretty basic and straightforward to me. I have a Weller 25 watt standard duty soldering iron kit (750*) and Bernzomatic 0.062", lead-free, silver bearing acid core solder to work with. I'm confident these will do the trick nicely, unless someone says there's something really obviously wrong to my unobvious eyes???


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## greco (Jul 15, 2007)

PickALick said:


> Well i've got a Chinese Bullet here that's waiting a few mods i'm dying to try, so I guess it's "sink or swim" time. What's the worst that'll happen - it won't work, right?!?!?!?
> 
> :/ RIGHT????????????????????
> 
> ...


Are you sure you want to use acid core solder?


*Solder*The choice of solder is also important. There several kinds of solder available but only a few are suitable for electronics work. Most importantly, you will only use _rosin core solder_. *Acid core solder is common in hardware stores and home improvement stores, but meant for soldering copper plumbing pipes and not electronic circuits. If acid core solder is used on electronics, the acid will destroy the traces on the printed circuit board and erode the component leads. It can also form a conductive layer leading to shorts.
*








For most printed circuit board work, a solder with a diameter of 0.75MM to 1.0MM is desirable. Thicker solder may be used and will allow you to solder larger joints more quickly, but will make soldering small joints difficult and increase the likelihood of creating solder bridges between closely spaced PCB pads. An alloy of 60/40 (60% tin, 40% lead) is used for most electronics work. These days, several lead-free solders are available as well. Kester "44" Rosin Core solder has been a staple of electronics for many years and continues to be available. It is available in several diameters and has a non-corrosive flux.
Large joints, such as soldering a bracket to a chassis using a high wattage soldering gun, will require a separate application of brush on flux and a thick diameter solder of several millimeters.
Remember that when soldering, the flux in the solder will release fumes as it is heated. These fumes are harmful to your eyes and lungs. Therefore, always work in a well ventilated area and avoid breathing the smoke created. Hot solder is also dangerous. It is surprisingly easy to splash hot solder onto yourself, which is a thoroughly unpleasant experience. Eye protection is also advised.

Cheers

Dave


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## PickALick (Aug 4, 2012)

greco said:


> Are you sure you want to use acid core solder?
> 
> 
> *Solder*The choice of solder is also important. There several kinds of solder available but only a few are suitable for electronics work. Most importantly, you will only use _rosin core solder_. *Acid core solder is common in hardware stores and home improvement stores, but meant for soldering copper plumbing pipes and not electronic circuits. If acid core solder is used on electronics, the acid will destroy the traces on the printed circuit board and erode the component leads. It can also form a conductive layer leading to shorts.
> ...


THANK YOU SOOOOO much for the heads-up man!!!!!!!!!!!!! Looks like I will stop by the local The Source or Canadian Tire on the way home tomorrow before rushing into a mistake tonight. 

Thankyouthankyouthankyouthankyouthankyouthankyou!!!!!!!!!!!!!!!!


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## greco (Jul 15, 2007)

PickALick said:


> Thankyouthankyouthankyouthankyouthankyouthankyou!!!!!!!!!!!!!!!!


YouarewelcomeYouarewelcomeYouarewelcomeYouarewelcome

cheers

Dave


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## PickALick (Aug 4, 2012)

So here I am sizing up an order with StewMac that i'd have sent State's side, then pick up myself (because I have NO patience for Canada Customs). I figure "what the heck, i'll throw in a soldering station and such", right?

*scratches head* Either i'm blind or they have everything, and I mean eeeeeeevery-f'n-THING but soldering-related stuff of any kind.

Really?!?!??! :/


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## PickALick (Aug 4, 2012)

Amazon dot ca to the rescue ... 

(Greco's favourtire) Weller WLC100 40-Watt Soldering Station: Amazon.ca: Electronics

Thanks again for the help, Dave!


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## greco (Jul 15, 2007)

PickALick said:


> So here I am sizing up an order with StewMac that i'd have sent State's side, then pick up myself (because I have NO patience for Canada Customs). I figure "what the heck, i'll throw in a soldering station and such", right?
> 
> *scratches head* Either i'm blind or they have everything, and I mean eeeeeeevery-f'n-THING but soldering-related stuff of any kind.
> 
> Really?!?!??! :/


*SHYTE...you beat me with your post 15.....LOL*

I don't think that StewMac carries soldering equipment and supplies. If they do, I'm blind also.

I'm not sure who would have the best prices for soldering stations and/or irons.
ABRA in Montreal seems reasonable.

This is an example from A-1 Electronics ...they might be not too far from you.
I have never been there.

The Weller brand is respected, but this might be fine.

Hope others comment. 

A1 Electronic Parts - Serving the Toronto area for 30 years!











*SR-998

$49.00*

Power consumption​15W - 60WSize of soldering iron220mmSize of machineL135mm * W95mm * H52mmWeightWeightAC Power cord3pin plug 180cm


*ADJUSTABLE ELECTRONIC SOLDERING STATION *


The SR-998 adjustable electronic soldering iron is a easy adjustable welding equipment. 

The temperature adjustment range from 15w to 60w. 

Choose the exact watts you need for your soldering applications.​*Soldering Tips for* *SR-998







**$4.60 / each*​Cheers 

Dave


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## loudtubeamps (Feb 2, 2012)

PickALick said:


> Amazon dot ca to the rescue ...
> 
> (Greco's favourtire) Weller WLC100 40-Watt Soldering Station: Amazon.ca: Electronics
> 
> Thanks again for the help, Dave!


Canadian Tire used to sell these.It might save U some shipping costs if it's still available.
As well The Source has an inexpensive 60 watt pencil with a variable temp. control mounted in the pencil.
Very handy and a good price for the average hobbyist.
I have first hand experience with these as I keep one in my toolkit for repairs away from home.
NexxTech™ 60W Soldering Iron with Variable Wattage | Soldering tools & supplies | Ratings & Reviews | TheSource.ca

If you want to invest in a good portable iron Catalog No. WPA2 Product Detail
I have had one of these for over 10 years. I keep it in my gig bag:Very Handy!


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## mhammer (Nov 30, 2007)

If one has any intention of modding or repairing gear, you want at least 40w of soldering power and as pointy a tip as you can get.

Why? Because mosr manufacturers are using lead-free solder these days, which has a higher melting temperature. With greqter miniaturization, you lso need atip fine enough to solder THIS without un/sodering THAT.


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## greco (Jul 15, 2007)

mhammer said:


> .......most manufacturers are using lead-free solder these days, which has a higher melting temperature.


Mark...Do you know if it will be impossible (or extremely difficult) to get lead based solder in the near future? If that is the case, I'm going to buy some extra.

Cheers

Dave


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## noman (Jul 24, 2006)

I might also add that to measure the pot with your friendly DMM, connect the leads to the outside tabs on the pot..........


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## mhammer (Nov 30, 2007)

greco said:


> Mark...Do you know if it will be impossible (or extremely difficult) to get lead based solder in the near future? If that is the case, I'm going to buy some extra.
> 
> Cheers
> 
> Dave


I don't know that solder with lead will be outlawed here any time in the near future, so you should still be able to buy old stock at any local electronics distributor. For the moment, the Rohs requirement is for commercial manufacturers who wish to sell in Europe and East Asia. You'll still be able to repair or mod your own equipment, assuming you aren't shipping it overseas, and I can't imagine any sort of enforcibility when it comes to Kijiji-based resale. So, for all intents and purposes, good old 63/37 or 60/40 is fine for us types. If you have dreams of being the next stompbox tycoon, however, better get used to the lead-free stuff.


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## PickALick (Aug 4, 2012)

mhammer said:


> ..... If you have dreams of being the next stompbox tycoon, however, better get used to the lead-free stuff.


Stompbox tycoon? Nah, but sought-after luthier would be nice.  

Since we're here ... what's the diff between the two? Besides the obvious lead versus not, eh. What changes from a workability standpoint? 

AWESOME thread!!!!!!!!!!!!!


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