Question for those who own PCB's

I've been collecting PCB's for a while now and have noticed on a number of mine that there will be a capacitor that's usually loose/wiggly. A friend of mine told me they were cold solder joints, where the solder cracks around the component.

My question is, though all the games play fine now is this somthing I should be concerned about for the future? Will leaving them the way they are be safe long term or should I find someone to solder them back tight?

Cold solder joints are easily fixed by just heating up the joint with a soldering iron. That causes the solder to melt and reflow.

Briggs, thanks for the quick reply. So no extra solder is needed, just heat up the joint and it will stiffin back up? Why do cold solder joints happen?

Also, how long should the soldering iron be held on the joint? I don't want to over heat and kill my capacitor.

if you want to spend $30(CND)... a retailer in canada called- canadian tire-.. got one of them cold solder gun.
here the site just copied and paste
http://www.canadiantire.ca/assortme...4443277565&assortment=primary&fromSearch=true
they sell like hot cakes..

Is that Cold Heat??

racecar said:

if you want to spend $30(CND)... a retailer in canada called- canadian tire-.. got one of them cold solder gun.
here the site just copied and paste
http://www.canadiantire.ca/assortme...4443277565&assortment=primary&fromSearch=true
they sell like hot cakes..

Click to expand...

RiotoftheBlood said:

Is that Cold Heat??

Click to expand...

I got one of these Cold Heat Solder Irons for Christmas..
I want to use it on something soon..

But,what gauge solder does PCBs usually have..?


Great for all general soldering applications
Heats and cools almost instantaneously for comfort and safety
Cordless operation
Reaches 800°F in less than one second
Tip cools to touch-safe temperature within four seconds
Very safe tip - hot only during active soldering
Red LED acts as tip heat indicator; super bright LED work light offers enough light to use the product in complete darkness
Works with any regular 18-25 gauge solder

I think when it's talking about what gauge solder it's referring to a roll of solder, not pre-used solder.

Now, I'm not sure how the Coldheat thing works...but I've heard it makes a spark to generate its heat, and that may not be good for a PCB. Someone with more knowledge as to how they work should say something about it.

Hmmm, I'm hearing lots of different stuff. I'd just like to know the safest most reliable way to fix my boards wobbly caps.

I'm just wondering: how will it affect to a board if just one out of the dozens of caps there gets loose and falls? Will the board still work?

chris1 said:

I got one of these Cold Heat Solder Irons for Christmas..
I want to use it on something soon..

But,what gauge solder does PCBs usually have..?


Great for all general soldering applications
Heats and cools almost instantaneously for comfort and safety
Cordless operation
Reaches 800°F in less than one second
Tip cools to touch-safe temperature within four seconds
Very safe tip - hot only during active soldering
Red LED acts as tip heat indicator; super bright LED work light offers enough light to use the product in complete darkness
Works with any regular 18-25 gauge solder

Click to expand...

Damn you mean to tell me that those actually work.

A condensator was loose on my Salamander 2 romboard. Traced, checked, measured - turns out it didnt do jackshit, so I let it stay.

Amano Jacu said:

I'm just wondering: how will it affect to a board if just one out of the dozens of caps there gets loose and falls? Will the board still work?

Click to expand...

It really depends on the function of the capacitor. MrLonghair for instance is probably talking about a bypass capacitor. If you look at a MVS board you'll notice that near every IC there is a blue cap. These are bypass caps and are across the ground and voltage connections of the IC. They are meant to reduce the amount of noise/ripple due to voltage fluctuations that can cause the IC to operate incorrectly (if the fluctuations are very big). Now, if you remove one of these caps the circuit (and the board) still works but it's open to that kind of problem which may lead to malfunction sooner or later.

Some interesting posts but I'd still like to know how to safely fix my loose caps.

If I use a soldering iron how long should it be held on the joint? I've heard parts can overheat rather quickly and don't want to ruin my boards.

The Chief said:

Some interesting posts but I'd still like to know how to safely fix my loose caps.

If I use a soldering iron how long should it be held on the joint? I've heard parts can overheat rather quickly and don't want to ruin my boards.

Click to expand...

As long as it takes the solder to melt /flow and re-establish a good electrical connection.
Add a little "fresh " solder, otherwish it may not flow. Do not overdo it.
Use resin core 60tin/40lead say 1mm diam solder.

ttooddddyy said:

As long as it takes the solder to melt /flow and re-establish a good electrical connection.
Add a little "fresh " solder, otherwish it may not flow. Do not overdo it.
Use resin core 60tin/40lead say 1mm diam solder.

Click to expand...

Thanks for the advise, I'll have to find some of that solder.

...I was just writing this then I noticed ttooddddyy posted..


I guess I'll still post it..

I'd say,If you see a significant wobble as where the solder joints are making and not making a solid contact with the pcb.
Then they should be re-soldered..I've done it a few times.
Sometimes you may need to add a tiny bit of solder to build up the connection again..

I wonder what happens with the sandwich type layered boards...What then..(If applies to the question
Actually messing with something and getting solder melted in-between the boards will or can that cause a problem..(?)

Fixing the cold solder joints I guess comes with experience..
I'd say if someone never soldered before then to practice on something that is shot..Bust open an electronic toy etc..
Also depends on just what tools your using...What do you have..?
I have several types of soldering irons....I mostly use a fine tipped soldering iron to do such type work.....But,I don't have anything expensive.
I still have to try out the Cold Heat/cordless Soldering Tool..
IMO..I don't think the 4 AA batteries it uses are going to put out that much heat...At least for long.

I would just try and heat the solder until you see it turn to liquid then stop.
If enough solder is on the joint it should solidize against the pcb.

On multilayered boards there is a copper tube that goes through the entire board(where through-hole parts are anyway), so the melted solder will only get to that.

Typically once the solder melts, you can keep the iron on it for 2-3 seconds to give it time to fully flow in/around the hole. And remember...it is heat that melts the solder, NOT pressure When I did assembly/repair at Hitachi many new people would try pushing onto the joint which can cause damage easily. Just rest it gently on the joint.

In a nutshell, the Cold Heat iron works this way: this tip is split into two halves. When solder, wire, etc. (anything conductive) is applied to the tip (between the two halves), the circuit is completed and the iron heats up.

I have one, but I haven't used it yet. I read about it a few months ago when someone posted about it, then I saw it at Costco for $15.99... cheap enough that I thought it was worth trying (if any of you are having trouble finding one, I may be able to help). I keep it in my truck. I also have a cordless butane iron, which I carry with me at work. I thought that the Cold Heat would be better for the truck because it doesn't use gas.

As far as using it for PCB work, from what I've read in the manual, I'd be cautious, at least if you have the Coleman brand. The manual basically states that it's meant for light-duty electrical work, and not recommended for sensitive electronics. Will it damage a capacitor or IC? I don't know, but it's not going to replace my standard iron.

Mone came with a bevel tip, which is fairly wide, and not ideal for small electronic components. You can buy conical and chisel tips, but they seem to be difficult to find.

Reznor007 said:

I think when it's talking about what gauge solder it's referring to a roll of solder, not pre-used solder.

Now, I'm not sure how the Coldheat thing works...but I've heard it makes a spark to generate its heat, and that may not be good for a PCB. Someone with more knowledge as to how they work should say something about it.

Click to expand...